Seminars and Colloquia

Title Speaker Location Material
Modelling SiPM photo-detection efficiency at TRIUMF Austin de St. Croix, TRIUMF CENPA Conference Room NPL-178

Silicon photomultipliers (SiPMs) have become the technology of choice for light detection, in applications from medical imaging to rare event searches and collider physics. SiPM’s behavior and nuisance parameters depend strongly on operating conditions, including the applied voltage and temperature. SiPM’s also produce external cross-talk photons which can have a significant impact on detector performance. Lastly, their photo-detection efficiency (PDE) depends strongly on the photon’s wavelength, angle of incidence and operational voltage. Thus to fully understand detector response, including the impact of external cross-talk, SiPM PDE must be understood over a large parameter space.

This talk will give a brief overview of SiPMs and the R&D efforts at TRIUMF. The talk will then focus on our novel model for SiPM PDE, which has been successfully applied to UV sensitive Hamamatsu and FBK devices. This model aims to benefit all detectors using SiPMs where detailed detector response is required.

Zoom link:

Development Of Cryogenic Scintillation Detectors For The Search Of New Physics Keyu (Coco) Ding CENPA Conference Room NPL-178

Coherent elastic neutrino-nucleus scattering (CEvNS) was first proposed in 1974. Despite having the largest cross-section among all low-energy neutrino couplings predicted in the Standard Model (SM), CEvNS detection remains challenging due to its only experimental signature being a low-energy nuclear recoil. In 2017, the COHERENT collaboration successfully observed CEvNS for the first time. A 14.6 kg low-background doped CsI at room temperature was placed 20 meters away from the 1.4 MW Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL). The SNS's pulsed proton beam provides exceptional background rejection and high-intensity neutrinos, making it ideal for CEvNS detections. CryoCsI, the proposed prototype, is a cryogenic undoped CsI scintillating detector, which has a much lower energy threshold potentially down to 0.5 keV_nr compared to the doped CsI.  This enhanced sensitivity of CryoCsI allows for the observation of more CEvNS events. Precise measurements of CEvNS can not only validate the predictions of the SM but also utilize CEvNS as a background for exploring new physics. By collaborating with other COHERENT detectors, CryoCsI has the potential to achieve world-leading sensitivities in a broad range of physics topics within and beyond the SM. Development and sensitivities of CryoCsI to hidden-sector dark matter and non-standard neutrino interactions are explored.

Pushing physics boundaries with precise timing Simone Mazza, UC Santa Cruz CENPA Conference Room NPL-178

We are currently in a period in time where there's no clear path forward in the field of particle physics. After the discovery of the Higgs boson the Standard Model is apparently complete. However, many cracks are starting to appear in the Standard Model (e.g. the recent g-2 result). Therefore, it is imperative for the physics community to push even more for new horizons. This effort must include both large-scale experiments (like Higgs factories or the FCC-hh) and small-scale experiments (like PIONEER). The development of crucial technology is imperative in both categories of experiment. My research is focused on discovering what’s beyond the Standard Model; to enable this effort I’m developing timing sensors to achieve full 4D (x,y,z,t) tracking. I’m mostly an expert in Low Gain Avalanche Detectors (LGADs), which are thin silicon detectors with modest internal gain with extremely good time resolution (down to <20ps). PIONEER, in which I’m heavily involved, is a next-generation experiment to measure the charged-pion branching ratio to electrons vs. muons and the pion beta decay with an order of magnitude improvement in precision. I’m positive that PIONEER will be a small experiment with a big impact. In this seminar, I’ll also introduce the ePIC detector at the electron-ion collider, its physics program and how fast timing is crucial to achieve its baseline performance. There will also be a brief overview of future colliders.

nEXO and the search for neutrinoless double beta decay Brian Lenardo, SLAC CENPA Conference Room NPL-178
The discovery that neutrinos have nonzero, but inexplicably small, masses hints that these particles may hold a key to physics beyond the Standard Model. In this talk, I will discuss the search for neutrinoless double beta decay (0νββ), a proposed form of radioactive decay which is only possible if neutrinos and antineutrinos are their own antiparticles. A discovery of 0νββ would immediately demonstrate new physics, specifically establishing a) violation of lepton number conservation, b) the generation of neutrino masses by a mechanism other than the Higgs, and c) possible connections between neutrino interactions and the dominance of matter over antimatter in the universe. In this talk, I will describe the next generation of these experiments, focusing in particular on the nEXO experiment. nEXO is designed to push two orders of magnitude beyond the reach of current experiments, which requires the ability to detect just one 0νββ decay event per year in a volume of ~10^28 atoms. I will describe how nEXO will achieve this exquisite sensitivity, then discuss how its unique capabilities may enable other science in the field of particle astrophysics. I will close with a discussion on scaling up the techniques used by nEXO to enable beyond-the-next-generation searches for new physics.


The Crucial Role of Underground Argon in Rare-Event Searches Thomas Thorpe, Los Alamos National Laboratory CENPA Conference Room NPL-178

The upcoming LEGEND-1000 and DarkSide-20k experiments are examples of neutrinoless double decay and direct dark matter searches that will reach
unprecedented exposures of 10 and multi-hundred ton-years, respectively. With this comes unprecedented radioactive background rates, which must be suppressed.
Argon sourced from underground CO2 wells (UAr) has been shielded from cosmogenic activation, and provides a powerful medium in which large, rare-event searches can be effectively performed. The crucial role UAr plays in the LEGEND-1000 and DarkSide-20k experiments will be emphasized. DarkSide-20k cryogenic experience, proper handling techniques, strategies undertaken to maximize light yield, and other applications in the search for rare events will be discussed.

Why reinvent the wheel? The case for LEGEND and DarkSide technological overlap Claudio Savarese, PhD CENPA Conference Room NPL-178

Why reinvent the wheel? The case for LEGEND and DarkSide technological overlap


Advances in instrumentation drive transformative discoveries in Particle Physics. The development of large-mass experiments with granular readout systems is pushing the boundaries of rare event searches.

Two of the most exciting endeavors of Modern Physics, shedding light on the nature of neutrinos and directly observing Dark Matter (DM), might well be within the reach of the next generation of detectors. I will introduce the LEGEND and DarkSide experiments and highlight the shared underpinning technologies and techniques.

The DarkSide program relies on dual-phase Time Projection Chambers to probe the dark matter parameter space with unprecedented sensitivity and over a vast range of candidate masses. The LEGEND experiment aims to observe the hypothetical neutrinoless double-beta decay of Germanium-76, thus proving that neutrinos are Majorana fermions.

Although very different in scope and energy range, these experiments share similar background suppression needs. I will detail the development of the DarkSide-20k photo-detection system and the strategy for procuring its DM target made of ultra-pure argon. I will then show how these elements can be adapted to aid the design of LEGEND

Precision Tests of the Standard Model: The Project 8 and Muon g-2 Experiments Christine Claessens, UW CENPA Conference Room NPL-178; Zoom link:
The Standard Model of Particle Physics is highly successful at predicting a wide range of phenomena. Only few experimental results have shown discrepancies with theory, indicating potential areas for new physics. Project 8 and Muon g-2 are both exploring discrepancies with Standard Model predictions through high-precision measurements. Project 8 aims to measure the neutrino mass, which is assumed to be zero within the Standard Model framework. Using Cyclotron Radiation Emission Spectroscopy to analyze tritium decay, Project 8 targets an unprecedented sensitivity to the neutrino mass of 40meV. The Muon g-2 experiment at Fermilab measures the anomalous magnetic moment of the muon, which is in tension with theory predictions, by injecting a polarized muon beam into a magnetic storage ring. In 2023, the collaboration released a new result, confirming previous measurements and reducing the uncertainty of the experimental world average to 0.19ppm. I will present the latest results from Project 8 and highlight the experiment’s journey toward achieving its ultimate sensitivity goal. I will further discuss recent advances in the Muon g-2 experiment, specifically the development of a new scintillating fiber detector enabling direct beam dynamics studies with high-statistics data, promising to further reduce the experiment’s systematic uncertainty.


The origin of flavour: from the Higgs boson to rare pion decays Quentin Buat, UW CENPA Conference Room NPL-178, Zoom link:

The elementary fermions we discovered so far are arranged in three flavours in the Standard Model of Particle Physics (SM). While the model has been extremely successful at describing properties like their mass hierarchies and mixings through this flavour structure, it fails short at explaining them. In this talk, I will present two avenues where measurements of SM quantities can point us toward a theory of flavour. The first one employs the ATLAS experiment at the LHC where the tau lepton — the heaviest cousin of the electron— offers the opportunity to study the Yukawa interaction responsible for the mass hierarchy of the fermions. The second avenue makes use of rare pion decays, a pristine probe of lepton flavour universality and quark mixing. PIONEER, a next-generation experiment proposed at the Paul Scherrer Institute, is set to improve the precision of rare pion decays ten-fold over current experiments. I will give an overview of the project and present the challenges and promises of the detector design.

Recording (requires NetID)

Search for solar neutrino and light dark matter with the PandaX-4T experiment Wenbo Ma CENPA Conference Room NPL-178

The PandaX-4T experiment aims to search for potential dark matter interactions. With significant technical improvements, PandaX-4T achieves unprecedented sensitivity at the low-energy edge of LXe detectors, opening a new window for observing solar neutrinos. Using commissioning data, two hybrid analyses are carried out to search for dark matter interactions, yielding world-leading results for neutrino-nucleus coherent elastic scattering from solar B8 neutrino, as well as for dark matter interactions with nucleons and electrons. These results demonstrate PandaX-4T's unique capability to search for low-energy interactions from solar and galactic sources.

Building Next-Generation AI for Neutrinoless Double-Beta Decay Searches Aobo Li CENPA Conference Room NPL-178

The discovery of Majorana neutrinos would fundamentally revise our understanding of physics and the cosmos. Currently, the most effective experimental probe of the Majorana neutrinos is neutrinoless double-beta decay(0vββ). Meanwhile, the explosive growth of artificial intelligence over the last decade has brought new opportunities to 0vββ experiments. Next-generation AI algorithms could break down significant technological barriers and deliver the world's most sensitive search for 0vββ. This talk will discuss one such algorithm--KamNet, which plays a pivotal role in the new result of the KamLAND-Zen experiment. With the help of KamNet, KamLAND-Zen provides a limit that reaches below 50 meV for the first time and is the first search for 0νββ in the inverted mass ordering region. Looking further, the next-generation 0vββ experiment LEGEND has created the Germanium Machine Learning group to pursue a complete AI analysis chain. As the odyssey continues, AI will enlighten the bright future of 0νββ and fundamental symmetries in general.

Low-Noise Amplifiers for Active Axion Search Experiments at IBS/CAPP Sergey V. Uchaikin, Institute for Basic Science, Center for Axion and Precision Physics Research, Daejeon, Republic of Korea CENPA Conference Room NPL-178

IBS/CAPP in South Korea is home to multiple active axion search experiments using cavity haloscopes that operate within the frequency range of 1-6 GHz. The haloscopes convert axions to photons, resulting in an output power of about 10-24 to 10-22 W. To detect such a small signal amidst noise, quantum-limited noise amplifiers and ultra-low temperatures (mK) are required for all critical read-out components to minimize noise from passive lossy components. Additionally, operating at low dissipation levels is necessary to maintain the haloscope and amplifier at a temperature of 25-40 mK. Our primary objective is to achieve the highest possible scanning frequency speed, which includes time for maintenance and system calibration.

For the CAPP-MAX flagship experiment, we achieved a speed of 3 MHz/day for DFSZ-level axion sensitivity during uninterrupting measurements. The report presents the development and operation of low-noise amplifiers for several haloscope experiments targeting different frequency ranges and provides design, operational, and performance details of the amplifiers.

Model-Independent BSM Physics Searches using Rare-Isotope-Doped Superconducting and Optomechanical Sensors Kyle Leach, PhD Physics-Astronomy Building (PAB); Room C520

High-precision measurements of energy and momentum conservation in weak nuclear decay are powerful, model-independent probes of new physics from the eV to TeV scale.  Significant advances in rare isotope availability and quality, coupled with decades of measurement technique development from the AMO community have led us into a new era of fundamental tests of Nature using unstable nuclei.  For the past few years, we have taken the approach of embedding short-lived radioisotopes in superconducting tunnel junctions to precisely measure the eV-scale recoiling atom produced in nuclear electron capture. Since these recoils are encoded with the fundamental quantum information of the decay process, they provide a unique probe of nuclear/neutrino entanglement, decoherence, and quantum localization in radioactive decay.  The recoils also carry signatures of weakly coupled BSM physics, including neutrino mass, exotic weak currents, and potential “dark” particles created within the Q-value window of the decay.  As a result, these measurements provide a complimentary and (crucially) model-independent portal to the dark sector with sensitivities that push towards synergy between laboratory and cosmological probes. In this talk, I will discuss the broad program we have developed to provide leading limits in these areas -- particularly for heavy BSM physics in the neutrino sector -- as well as the technological advances across several sub-disciplines of science to push this technique towards “on-line” measurements of short-lived systems at FRIB.  Finally, I will discuss future prospects of using macroscopic amounts of harvested rare isotopes in optically levitated nanospheres for direct momentum measurements of the decay recoils using truly quantum sensing techniques for dramatically improved sensitivity to new physics.

Search for Dark Matter Axion with TASEH Yung-Fu Chen, Professor of Physics, Taiwan National Central University CENPA Conference Room NPL-178

TASEH (Taiwan Axion Search Experiment with Haloscope) devotes to search dark matter axions based on a haloscope setup, consisting of a frequency-tunable microwave cavity detector in a strong magnetic field and a signal receiver. The TASEH experiment targets axion searches in the mass range of 10–25 μeV, roughly corresponding to the frequency band of 2.5–6 GHz. In this presentation, we will describe our first physics search, which excludes values of the axion-photon coupling constant above 8.1 × 10^-14 inverse GeV, a factor of 11 above the KSVZ benchmark model, in the mass range of 19.4687–19.8436 μeV. We will also illustrate our subsequent efforts on improving the detection sensitivity up to the QCD axion-photon coupling limit, including developing a large-volume conic shell-cavity detector and integrating a quantum-limited Josephson parametric amplifier to the readout chain.


Precision Metrology with Photons, Phonons and Spins: Answering Major Unsolved Problems in Physics and Advancing Translational Science Dr. Michael Tobar CENPA Conference Room NPL-178

The Quantum Technologies and Dark Matter research laboratory has a rich history of developing precision tools for both fundamental physics and industrial applications. This includes the development and application of novel low-loss and highly sensitive resonant photonic and phononic cavities, such as whispering gallery and re-entrant cavities, as well as photonic band gap and bulk acoustic wave structures. These cavities have been used in a range of applications, including highly stable low noise classical and atomic oscillators, low noise measurement systems, highly sensitivity displacement sensors, high precision electron spin resonance and spin-wave spectroscopy, high precision measurement of material properties and applications of low-loss quantum hybrid systems, which are strongly coupled to form polaritons or quasi-particles. Translational applications of our technology has included the realization of the lowest noise oscillators and systems for advance radar, the enabling of high accuracy atomic clocks and ultra-sensitive transducers for precision gravity measurements. Meanwhile, there is currently a world-wide renascence to adapt precision and quantum measurement techniques to major unsolved problems in physics. This includes the effort to discover “Beyond Standard Model” physics, including the nature of Dark Matter, Dark Energy and the unification of Quantum Mechanics with General Relativity to discover the unified theory of everything. Thus, the aforementioned technology has been adapted to realize precision measurement tools and techniques to test some of these core aspects of fundamental physics, such as searches for Lorentz invariance violations in the photon, phonon and gravity sectors, possible variations in fundamental constants, searches for wave-like dark matter and test of quantum gravity. This work includes: 1) Our study and application of putative modified physical equations due to beyond standard model physics, to determine possible new experiments: 2) An overview of our current experimental program, including status and future directions. This includes experiments that take advantage of axion-photon coupling and axion spin coupling to search for axion dark matter. High acoustic Q phonon systems to search for Lorentz violations, high frequency gravity waves, scalar dark matter and tests of quantum gravity from the possible modification of the Heisenberg uncertainty principle.

Comparing accurate theoretical predictions with novel precision beta-decay experiments on 6He and 23Ne Ayala Glick-Magid CENPA Conference Room NPL-178

Multiple high-precision β-decay measurements are being carried out these days on various nuclei, in search of Beyond the Standard Model signatures. Those necessitate very accurate Standard Model theoretical forecasts to be compared with. Motivated by the experimental surge, I will present a general formalism for a precise calculation of β-decay observables, with controlled accuracy, based on a perturbative analysis of the theoretical observables related to the phenomena, including, e.g., high-order nuclear recoil and shape corrections. The accuracy of the corrections will be analyzed by identifying a hierarchy of small parameters, related to the low momentum transfer characterizing β-decays. Concentrating on nuclei relevant to the ongoing experiments, I will examine highly accurate standard model numerical forecasts of the β-neutrino correlation coefficients and β-energy spectrum for 6He and 23Ne, compare them to existing as well as new measurements and show new significant constraints on the Standard Model.

High Precision Experiments with Cold and Ultra-Cold Neutrons Hartmut Abele CENPA Conference Room NPL-178

The Neutron and Quantum Physics Group at TU Wien pursues various research
approaches in the field of particles and cosmology. In this talk, I will present precise
symmetry tests of various kinds, which are coming within reach with neutron decay facility
PERC at Munich research reactor FRM2 or at ESS, the European Spallation Source. In focus
are searches for possible deviations from the Standard Model (SM) of particle physics with
cold and ultra-cold neutrons. Next, we present a novel direct search strategy with neutrons
based on a quantum bouncing ball in the gravity potential of the earth. The aim is to test the
law of gravitation with a quantum interference technique, providing constraints on dark
matter and dark energy.

Physics across thirty orders of magnitude in time Kevin Croker CENPA Conference Room NPL-178

This talk is a double feature, beginning with "oscilloscope on chip" instrumentation and finishing with stellar remnant phenomenology over cosmic time.  The Large Area Picosecond Photo-Detector (LAPPD) is an attractive single photon detection technology when high surface area and low noise are design requirements.  The Instrumentation Development Lab (IDLAB) at U. Hawaii, in collaboration with Ultralytics, LLC., has developed "plug-n-play," low-power, 5 GSPS readout electronics that mount directly to Incomm LAPPDs for a maximally compact form factor.  We give an overview of this project, with emphasis on open-source software for configuration, control, and data acquisition at > 1Mpps using only commodity hardware. Roughly thirteen orders of magnitude slower in time, gravitational waveform observations from LIGO/Virgo and radio interferometry from the Event Horizon Telescope confirm that BHs are universally well-described by the Kerr solution.  The Kerr solution, however, is incompatible with our expanding universe on timescales comparable to the reciprocal expansion rate.  Known solutions with realistic boundary conditions can interact strongly with the universe at large, leading to numerous, testable, observational consequences in astrophysical systems ranging from the merging stellar mass binaries observable with LIGO/Virgo to ancient quasars.  We review the theoretical and observational status of one such phenomenon, cosmological coupling, and argue that the masses of BHs everywhere maybe always growing, without any accretion at all.

The Mu3e experiment Frederik Wauters CENPA Conference Room NPL-178

The Mu3e experiment will search for the Charged Lepton-Flavour Violation decay of the muon into two positrons and one electron. With a vanishingly small branching ratio in the Standard Model, any observation of this process will be clear evidence for new physics. A first phase of the experiment aiming for a single event sensitivity of one in 2e15 muon decays is currently under construction at the at the Paul Scherrer Institute in Switzerland. To achieve the envisioned sensitivity, we are building a low-mass pixel tracker complemented by timing detectors surrounding a muon target to reconstruct the full kinematics of candidate μ+ e+e+e events. An online FPGA- and GPU-based filter farm allows us to process over 10e8 muon decays per second. With all detector prototypes meeting specifications, sub-detectors are being constructed and integrated in the experimental apparatus during the ongoing engineering runs. In this presentation we report on the current status of the experiment, and our plans towards full detector commissioning and first physics data taking in two years from now.


Neutron Star Cooling: Clues about nuclear physics Mia Kumamoto CENPA Conference Room NPL-178

Neutron stars present a unique opportunity to observe high density, low temperature nuclear matter.  Cooling processes in neutron stars probe neutrino physics, the nuclear equation of state, superfluidity, phase transitions, and other properties of nuclear matter.  X-ray observations can constrain the neutrino emissivity of accreting systems.  In particular, observations of relatively cold systems with large neutrino emissivity indicates the presence of fast cooling mechanisms.  In this talk, I will review basic features of neutrino cooling in neutron stars and show that the x-ray transient SAX J1808 requires the presence of fast cooling processes.  Should a transition to deconfined quark matter occur at neutron star densities, this requirement puts limits on the critical temperature of different pairing channels in color superconducting quark matter.

A Random Walk from Academia to Industry: Jovian Plasma Bubbles, cryogenic antimatter, nuclear well-logging & commercial fusion Ben Levitt CENPA Conference Room NPL-178

I’ll discuss some experiences along the way from an early academic career in experimental plasma physics towards my current role, directing a private fusion company towards commercialization. The circuitous route begins and ends (so far) in high temperature plasma physics, but takes some twists through antimatter studies at CERN and even through the oil and gas industry. I’ll briefly cover some of these physics topics while focusing heavily on my current role at Zap Energy and the adventures of doing industrial physics research in a start-up.

Developing High-Pressure Gaseous TPCs for Neutrinoless Double Beta Decay Search Heng Lin, Shanghai Jiao Tong University CENPA Conference Room NPL-178

In the past decades, huge efforts have been put into unraveling the mysteries of neutrino mass generation (Majorana or Dirac). Neutrinoless double beta decay is one of the golden channels to detect Majorana neutrinos. We develop Time Projection Chambers (TPC) with high pressure gaseous 136Xe to search for Neutrinoless double beta decay. The TPCs use Micro-pattern gas detectors (Micromegas) as the charge readout, utilizing their tracking capability for event identification. A prototype detector holding 20 kg of gaseous xenon was successfully built and commissioned. The design and construction progress of a full-size detector containing 140 kg of xenon will be introduced. Track reconstruction and signal identification algorithms were also studied and developed, demonstrating significant signal-background discrimination power.

Search for the Absorption of Sub-MeV Fermionic Dark Matter on Electron Targets with the PandaX-4T Commissioning Data Dan Zhang, University of Maryland CENPA Conference Room NPL-178

PandaX-4T is a 3.7-ton liquid xenon time projection chamber (LXeTPC) operating at the China Jinping Underground Laboratory. An initial search for weakly interacting massive particles (WIMPs) has been recently completed with the commission data, leading to a tightest constraint to WIMP-nucleon interaction. On the other hand, light dark matter has attracted increasing attentions by the community recently, as a lot parameter space has yet to be explored. With the PandaX-4T commissioning data, this work searches for the absorption signal of a galactic sub-MeV dark matter (χ) via the channel χe → eν with an out-going active neutrino, where the mass of χ contributes to the recoiling energy of electrons. The keV-scale sterile neutrino is a representative of such a light fermionic DM, which has already been tightly constrained by astronomical X-ray observations. We found that if χ interacts with electrons and active neutrinos (ν) with an effective new interaction, PandaX-4T can be particularly sensitive to that with an axial-vector or vector mediator.

Searching for light Dark Matter with the DAMIC and DAMIC-M CCDs Michelangelo Traina, Sorbonne University CENPA Conference Room NPL-178

The DArk Matter In CCDs experiments at the SNOLAB and Modane underground laboratories aim for direct detection of light dark matter particles (m<10 GeV/c^2). Their fully-depleted, 675 um-thick Charge-Coupled Devices (CCDs) are characterized by electron-order readout noise and minimal leakage current (≲1E-3 e-/pixel/day). DAMIC at Modane CCDs additionally feature skipper readout amplifiers, which can achieve sub-electron resolution by means of repeated non-destructive charge measurements. This talk will detail the construction of the first comprehensive CCD background model in DAMIC at SNOLAB, and report on the deployment and science run of the DAMIC-M prototype detector, the Low Background Chamber (LBC).

Black holes and axions: from gravitational waves to axionic beacons Masha Baryakhtar CENPA Conference Room NPL-178

I will discuss how black holes can become nature's laboratories for ultralight axions. When a boson's Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons, creating a gravitational atom in the sky. Previously open parameter space of axions can be constrained by observations of rapidly spinning black holes. Such black hole-axion `gravitational atoms' can also source up to thousands of monochromatic gravitational wave signals visible in LIGO and VIRGO observatories. If the axions interact with one another, instead of gravitational waves, black holes populate the universe with low energy axion waves.

The ALPHA Collaboration and the Axion Plasma Haloscope Katherine Dunne CENPA Conference Room NPL-178
The newly formed ALPHA collaboration has begun work towards building a tunable, cryogenic, plasma haloscope using wire metamaterials. The plasma haloscope is a novel method for the detection of the resonant conversion of axions to photons. Traditional cavity and dielectric haloscopes compensate for the momentum mismatch between the axion and the massless photon by breaking translational invariance. In this case, reaching higher axion masses with sufficient sensitivity is a challenge due to the very small structures needed. Plasma haloscopes instead use a tunable plasma frequency to match the axion mass. The plasma frequency of a wire metamaterial can be tuned to match the axion mass by changing the interwire spacing, allowing for large conversion volumes. This talk will give an overview of the plasma haloscope concept and the ongoing experimental effort of the ALPHA collaboration.


Heavy Flavor Physics at LHCb and its current Upgrade Svende Braun zoom

Flavor Physics is a powerful way to search for physics beyond the Standard Model. Since 2010, the LHCb experiment at CERN has collected large datasets of b- and c-hadrons to carry out world-leading measurements in the field of flavor physics, thanks to its excellent detector performance. Many of these results would benefit from significantly larger data samples. To achieve this goal, LHCb will operate with a fully software-driven trigger system and read out collision data at a rate of 40MHz starting in 2022. This requires a major upgrade of the detector, currently underway at CERN: three new trackers as well as more powerful readout electronics are being installed, which will increase the data collection rate by a factor of 5. I will highlight some results from LHCb’s initial runs and discuss the ongoing upgrade efforts, with a focus on the silicon microstrip Upstream Tracker, and the resulting prospects for precision measurements in the flavor sector.

Recent progress from the PandaX experiment Jianglai Liu CENPA Conference Room NPL-178 and zoom

The PandaX (Particle and Astrophysical Xenon) experiment, located in the world deepest underground laboratory, China Jinping Underground Laboratory (CJPL), is dedicated to search for dark matter particles and to study fundamental properties of neutrinos. The current stage experiment, PandaX-4T, contains a sensitive time-projection-chamber with 3.7-ton liquid xenon target. The commissioning run of PandaX-4T has been completed in 2021. In this talk, after an overview of this project, I will present our first dark matter search with the commissioning data, and discuss future prospects of PandaX.

Detecting High-Frequency Gravitational Waves with Microwave Cavities Jan Schütte-Engel zoom
Constraining the Equation of State of Neutron-Rich Matter William Lynch CENPA Conference Room NPL-178

The GW observations and the recent constraints on neutron star radii from Neutron star Interior Composition Explorer (NICER) have provided some constraints on the relationship between total pressure and the matter density. Neither provides an independent constraint on the symmetry energy: the EoS term that arises from the imbalance of neutron and proton composition. The symmetry energy governs the proton fraction, the crust-core phase transition density and pressure, and possible transitions to D matter or to strange matter within neutron stars. I will discuss some experimental efforts to constrain the symmetry energy via experiments where its role can be controlled by varying the n-p imbalance and density of the system. I will discuss some of the results obtained to date and endeavor to put them into context with some of the astrophysical observations.

DANCE: Dark matter Axion search with riNg Cavity Experiment Yuta Michimura zoom

Axion and axion-like particles are leading candidates for ultralight dark matter, and there have been enormous efforts to search for their signatures through a variety of experiments and astrophysical observations. Axion may cause a polarization rotation of light through the parity-violating interaction with photons. Recently, we have proposed to search for axion dark matter by enhancing the polarization rotation effect using a bow-tie optical ring cavity [PRL 121, 161301 (2018)]. We have shown that this Dark matter Axion search with riNg Cavity Experiment (DANCE) can improve the sensitivity to axion-photon coupling for axion mass m_a<10^{-10} eV by up to several orders of magnitude, compared with the current best limits. Currently, a prototype experiment DANCE Act-1 is underway at Tokyo to demonstrate the feasibility of the method. In this talk, I will present the principle of DANCE and the status of DANCE Act-1, including some of the preliminary results from the first 12-day run in May 2021.

Precision Measurement of the Magnetic Field in the Muon g-2 Experiment at Fermilab Simon Corrodi zoom

The Muon g-2 Experiment published the first result for the anomalous magnetic moment of the muon obtained from data taken in 2018, which are in good agreement with the result from the former experiment at Brookhaven. The combined experimental result increases the tension with the Standard Model expectation from 3.7 sigma to 4.2 sigma, strengthening possible hints for new physics. This talk will present the precision measurement of the magnetic field with a focus on systematic uncertainties.

High-precision NMR frequency extraction method for the Muon g-2 Experiment Ran Hong zoom

The Muon g-2 Experiment (E989) at Fermilab measures the muon magnetic anomaly, and its first result has improved the uncertainty from 0.54 ppm (in the previous experiment E821) to 0.46 ppm. In this experiment, the storage ring magnetic field is measured using nuclear magnetic resonance (NMR) probes. The free induction decay (FID) signals from the NMR probes are analyzed using a high-accuracy frequency extraction method. The phase function of the FID is extracted via the Hilbert transform, and the FID frequency is then extracted by fitting the phase function to a polynomial. In this presentation, the development and implementation of this FID frequency extraction method will be described in detail. Systematic effects of artifacts and a method of mitigating these effects are discussed. A thorough investigation of the statistical uncertainties of this method will be presented as well. Correlations between noises of the phase function samples are studied for different noise spectra. We discovered that the error covariance matrix for the extracted phase function is nearly singular and improper for constructing the χused in the fitting routine. A down-sampling method for fixing the singular covariance matrix has been developed so that the minimum χ2-fit yields properly the statistical uncertainty of the extracted frequency.

Positron beam based detector characterisation and towards a future high precision calorimeter prototype for the MEG II experiment to search for charged lepton flavour violation and exotic physics Patrick Schwendimann zoom

The MEG II experiment aims to improve the sensitivity to the branching ratio of the charged lepton flavour violating decay μ→ e+γ down to × 1014. This marks an improvement by an order of magnitude with respect to the current best upper limit set by the MEG experiment. At this moment, the MEG II experiment is in its engineering run and will likely be able to take physics data towards the end of the year. I will present positron beam based detector characterisation methods developed in the context of this upgrade as well as simulations for a future upgrade of an auxiliary detector by a new prototype for future high precision calorimetry based on a large LYSO crystal coupled to SiPMs. Further, I will elaborate on the commissioning of the detector in general and on the detector hut temperature control subsystem to which I significantly contributed. Finally, I will offer an outlook to the future of the MEG II experiment and present two exotic physics cases which can be investigated with the MEG II apparatus.

The tritium loops system of the KATRIN experiment Alexander Marsteller zoom

The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium β-decay endpoint region with a sensitivity on mν of 0.2eV/c2 (90% CL). For this purpose, the 10^11 β-electrons per second from a high-luminosity windowless gaseous tritium source (WGTS) are analyzed by an electrostatic retarding spectrometer and those with energies near the endpoint of 18.6 keV are counted to obtain an integral spectrum. To keep the systematical uncertainties at the level required to reach the target sensitivity, the activity of this WGTS needs to be stable at the level of 0.1% while maintaining a throughput of 40 g/day of high purity tritium. This task is accomplished by the tritium loops system. 

In this presentation, the tritium loops system of KATRIN will be introduced and some challenges in operating a tritium containing system with high purity requirements and at low temperatures will be shown.

A Novel Large-Volume Axion Detector in the CM-Wavelengths: Promises and Challenges Chao-Lin Kuo zoom

The QCD axion simultaneously explains the smallness of neutron EDM and provides a compelling candidate for Dark Matter. In this talk, I will first highlight synergies between CMB (cosmic microwave background) cosmology and the search for QCD axion. I will then focus on the "axion-haloscope", which uses the inverse Primakoff conversion of axions in a resonant cavity under an external magnetic field. A conventionalhaloscope’s sensitivity decreases precipitously in frequency, making it difficult to probe the axion mass range in the cm-wavelengths (or >~ 10ueV). I will describe a novel experimental approach that can enhance the scan rate by several orders of magnitude using space-filling thin-shell cavities, including the promises and challenges. I will conclude by providing an outlook, and an update on our experimental effort to demonstrate a prototype.

Dark photons And Haloscopes Sumita Ghosh (Yale University) zoom

The dark (or hidden) photon is a massive U(1) gauge boson theorized as both a dark force mediator and a dark matter candidate. Dark photons can be detected with axion cavity haloscopes by probing for a power excess caused by the dark photon’s kinetic mixing with Standard Model photons. Haloscope axion exclusion limits may therefore be converted into competitive dark photon parameter limits via the calculation of a corresponding dark photon to photon coupling factor. This calculation allows for an improvement in sensitivity of around four orders of magnitude relative to other dark photon exclusions and may be attained using existing data. I will present this conversion and limits on the kinetic mixing coefficient between dark photons and the Standard Model photons based on existing haloscope axion searches. These limits can be further improved upon without lowering the sensitivity of the haloscopes to axions by modifying the angle of the cavity and the measurement time. I will also discuss how new haloscopes being developed for more sensitive axion measurements will improve dark photon exclusions. (arXiv:2104.09334)

Searches for CPT/Lorentz Invariance Violation with the Fermilab Muon g − 2 Experiment Breese Quinn, University of Mississippi CENPA Conference Room NPL-178

The Muon g 2 Experiment now running at Fermilab aims to resolve the current 3.7σ experiment-theory discrepancy in the anomalous mag- netic moment of the muon, aμ = (g 2)/2. Among the possible sources of new physics that could account for a non-zero value for aμ are CPT or Lorentz Invariance violations. Previous muon g 2 experiments have set the majority of the most stringent limits on Standard-Model Extension CPT and Lorentz violation in the muon sector. These limits are consistent with calculations of the level of Standard-Model Extension effects required to account for the current aμ discrepancy. The status and prospects of the Fermilab Muon g 2 Experiment searches for CPT/Lorentz violation will be discussed, and possibilities for additional new physics investigations at Muon g 2 using similar techniques will also be presented.


Recent Discoveries in Gravitational Wave Astrophysics Dr. Michael Ross (CENPA) Zoom

The LIGO and Virgo gravitational wave (GW) observatories recently finished their third observing run. Due to the increased sensitivity during this run, we detected GWs at a rate of roughly 1.5 events per week. I will give an overview of our recent GW catalog (GWTC-2) containing 39 events and will highlight a number of exceptional events. Through examining these events we will touch on a variety of phenomena from black hole populations and black hole formation channels to GW higher order modes and binary merger recoils.


Getting Close to Gravity: Developing the Experimental Techniques to Measure the Inverse Square Law of Gravity Down to 10-micrometer Mass Separations Conner Gettings Zoom link will be available via announcement email, or by contacting: wisecg[at]

Torsion balances are almost ideal detectors of weak forces due to their low stiffness, noise and sensitivity to ground tilt. Their dynamics, however, make it difficult to measure forces that have sub-mm ranges. In Birmingham we are developing the experimental techniques, based on previous work, to eventually allow reliable measurements of the inverse square law of gravity down to mass separations of the order of 10ľm. This work has revolved around the superconducting torsion balance and the proof-of-concept air bearing suspension projects. I will discuss these experiments and my involvement in them during my PhD. This has included designing, building and implementing a capacitive displacement sensor for measuring the rotation of the test mass of the superconducting torsion balance, experimentally demonstrating the in-situ tuning of the centre-of-buoyancy and rotational stiffness of a suspended mass on the air bearing suspension, as well as modelling the magnetic forces in the superconducting torsion balance.

Detection efficiency as systematic error source in Project 8 Christine Claessens Zoom link will be available via announcement email, or by contacting: en37[at]

The Project 8 collaboration aims to measure the absolute antineutrino mass scale from the distortion of the tritium beta decay spectrum near its endpoint. To this end, the collaboration has successfully established Cyclotron Radiation Emission Spectroscopy (CRES), a new frequency-based approach to detect electrons and determine their kinetic energy. Since the neutrino mass is determined from a modification of the shape of the tritium spectrum near its high energy endpoint, it is essential to quantify any dependence of the electron detection efficiency on energy or, equivalently, frequency. Incorporating this dependence in the analysis is crucial for an accurate measurement of the endpoint and the extraction of the neutrino mass. In this talk, I will present how the detection efficiency in the Project 8 Phase II experiment is measured and demonstrate its impact as systematic error source on the spectrum analysis of the first tritium spectrum recorded with CRES.


The Muon g-2 Experiment: Measuring the Muon’s Anomalous Magnetic Moment Dr. David Sweigart Zoom link will be available via announcement email, or by contacting: en37[at]

The measurement of the muon's anomalous magnetic moment has been a historic test of our theoretical understanding of elementary particles and their interactions.  At present, the world average is in tension with the value predicted by the Standard Model of particle physics by more than three standard deviations, possibly caused by new physics interactions.  To resolve this discrepancy, the Muon g-2 experiment at Fermilab aims to measure the muon's anomalous magnetic moment to a record 140 parts per billion using data taken over five years from 2018 to 2022.  The experimental method involves trapping a polarized beam of positive muons in a storage ring containing an extremely uniform magnetic field.  The difference in the muons' cyclotron and spin-precession frequencies - known as the anomalous precession frequency - is directly proportional to the muon's anomalous magnetic moment.  This talk motivates making an improved measurement of the muon's anomalous magnetic moment, outlines the experimental method, and describes the algorithm used to reconstruct the decay positrons impacting the electromagnetic calorimeters around the ring.  Using data taken in 2018, a blinded measurement of the muon's anomalous precession frequency to 410 parts per billion is then presented, which will allow the muon's anomalous magnetic moment to be determined with a precision comparable to that of the world average.

Exotic Molecules for Nuclear Science Prof. Ronald Garcia Ruiz Zoom link will be available via announcement email, or by contacting: en37[at]

Precise knowledge of the interaction between the atomic nucleus and the surrounding electrons offers a complementary insight into the atomic nucleus and the fundamental particles and forces of nature. Exotic molecules - those containing nuclei with extreme proton-to-neutron ratios - can be tailored to investigate particular details of electron-nucleon interactions and enhance their symmetry-violating properties. Thereby offering high sensitivity to access to unexplored nuclear phenomena, to study the violation of fundamental symmetries, and to search for new physics. In this talk, I will present recent results from laser spectroscopy experiments of these exotic species. The relevance of these results to some of the pressing questions of nuclear science will be discussed.

Online CENPA Seminar: Atomic Physics meets Nuclear and Beyond SM Physics Dr. Christian Schneider Zoom link will be available via announcement email, or by contacting: en37[at]
Atomic physics techniques offer extraordinary control over both motion and internal degrees of freedom of individual quantum systems.  This control has enabled the most accurate measurements e.g. in atomic clocks.  At the same time, precision measurements allow to test fundamental and SM physics at a level corresponding to energy scales accessible only by the largest colliders.  Two experimental efforts in this context will be presented in this talk.
The first experiment---within the HUNTER collaboration---is the search for keV-range sterile neutrinos, which present an interesting extension to the SM and could also be dark-matter constituents.  We will start with the first-ever magneto-optical trap for cesium-131 which undergoes electron capture.  The total reconstruction of the energies and momenta of the "visible" particles in a decay will be achieved with very high-resolution electrostatic ion and electron spectrometers, respectively, and state-of-the-art pixellated X-ray detectors.  This reconstruction will allow to deduce the mass of the undetected neutrinos and keV-range (sterile) neutrino events will appear as a well-separated signal from ordinary neutrino events.
The second experimental effort is the search for the nuclear isomeric transition in thorium-229.  Due to its exceptionally low energy, this transition is in the laser-accessible energy range around 150nm.  Its unique properties make it the prime candidate for precision nuclear and fundamental physics tests as well as future optical clocks.  Three experiments to narrow down the knowledge of the transition energy will be presented, all of which are currently conducted in parallel and exploit physically fundamentally different effects.
CANCELLED (MADMAX) Stefan Knirck CENPA Conference Room NPL-178
CANCELLED: Electroweak Physics at ATLAS Dr. Heather Russell Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM
Joint CENPA-EPE seminar
While the Standard Model (SM) of particle physics provides the current best description of the sub-atomic scale of the known Universe, there are many observations with which the SM cannot be reconciled.  Direct searches for beyond the SM (BSM) physics have thus far not discovered anything, and the possibility remains that any BSM particles are beyond direct reach of the Large Hadron Collider. Fortunately, precision measurements of the SM are also powerful indirect tests of BSM physics. I will discuss precision electroweak measurements performed at the ATLAS experiment, including measurements of vector boson scattering and the production of multiple vector bosons. These measurements help us both to better understand the SM and to perform generic searches for new phenomena through effective field theory decompositions.


Gravitational searches for compact dark matter objects Prof. Chuck Horowitz Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Recent observations of gravitational waves (GW) from merging black holes and neutron stars have opened up the GW sky.  What else could be out there?   Much of the Universe is made of unobserved dark matter.   It is attractive to search for dark matter with GW because dark matter is known to have gravitational interactions.  Dark matter could be composed of compact dark objects (CDOs). These objects may interact very weakly with normal matter and could move freely inside astronomical bodies. We calculate the expected GW signal for a CDO merging with a galactic neutron star.  We search data from the first advanced LIGO observing run for GWs from close CDO binaries orbiting inside the Sun.  A CDO moving in the inner core of the Earth will have an orbital period near 55 min and produce a time dependent signal in a gravimeter.   These devices measure the local gravitational acceleration.  We use data from a superconducting gravimeter, in an abandoned silver mine deep in the Black Forest of Germany, to rule out such objects moving inside the Earth unless their mass and or orbital radius are very small.

Looking for Majorana in All the Wrong Places Prof. André de Gouvêa Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

I will discuss different options for distinguishing Majorana from Dirac neutrinos, including neutrino scattering, neutrino decay, and searches for lepton-number violating processes other than neutrinoless double-beta decay (e.g. mu^- to e^+ conversion in nuclei). In the case of the less powerful probes of lepton-number violation, I will discuss concrete theoretical circumstances where they provide nontrivial information.

What do we really know about the proton? Dr. Iris Abt Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The proton is a particle which is all around and in us and has been studied in detail for many decades. But what do we really know about it? When the structure of the proton is discussed, do we really discuss the proton or QCD? Has the rise of the gluon distribution as observed at the ep collider HERA for high four-momentum-transfers, Q2, anything to do with the proton? And what happens at Q2 of about 1 GeV2 and below when perturbative QCD cannot be applicable? Can the proton spin puzzle really be solved? What is the "true" size of the proton and what is its shape? All these questions are discussed and some answers are offered.

Status of the Standard Model prediction for the anomalous magnetic moment of the muon Martin Hoferichter CENPA Conference Room NPL-178

The longstanding discrepancy between measurement and Standard Model prediction for the anomalous magnetic moment of the muon will soon be scrutinized with the release of Run-1 data from the E989 Fermilab g-2 experiment.  To be able to fully profit from the gains in experimental sensitivity, we need a Standard Model prediction with comparable uncertainties, which presents a challenge to theory mainly due to hadronic corrections.  In the talk, I will present the current status of the Standard Model prediction and discuss future prospects to meet the ultimate E989 precision goal.

Neutrino Oscillations with IceCube Prof. Sebastian Böser Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

With an instrumented volume of one gigaton, the IceCube neutrino observatory at the South Pole is the largest neutrino detector in the world. While initially deemed impossible to observe due to IceCube's high energy threshold, the low-energy infill array DeepCore has opened up the full breadth of neutrino oscillation physics. Exploiting the ubiquitous flux of atmospheric neutrinos, IceCube now not only provides important contributions to the measurement of the atmospheric mixing parameters. The very high rate of neutrino observations also allows for worlds most precise measurement of tau neutrino appearance, stringent limits on non-standard interactions of the neutrinos as well as on the existence of sterile neutrinos. The IceCube Upgrade scheduled for the austral season 2022/2023 will further boost the sensitivity in all oscillation analyses, and — in combination with the reactor neutrino experiment JUNO — will allow to resolve the question of neutrino mass ordering at 5σ confidence level.

New Results from CUORE Dr. Danielle Speller Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The CUORE (Cryogenic Underground Observatory for Rare Events) Experiment is a ton-scale, 988-bolometer array located deep underground in Gran Sasso National Laboratory (LNGS). CUORE is designed to search for the neutrinoless double-beta decay (0νββ) of 130-Te, a lepton-number-violating process that could point toward new physics beyond the standard model.  CUORE has collected over 369.9 kilogram-years of exposure, and is optimized for sensitivity to neutrinoless and two-neutrino double-beta decay.  In this talk, we discuss the recent results and current status of the CUORE experiment, and present recent results.

Higgs Boson decay as a probe to the unsolved mysteries in the Universe: dark energy, dark matter and missing antimatter Prof. Chunhui Chen Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Despite being a remarkably simple theoretical model, the Higgs mechanism is the only known theory that is connected to some of the most profound mysteries in the modern physics: dark energy, dark matter and missing antimatter. Measurements of the Higgs boson decay may shield lights on those open questions. In this talk, I will present a few selective results from the ATLAS experiment on the Higgs boson decays. Namely the first observation of the Higgs boson decay to a pair of b-quarks, which had eluded us for many years despite it is the most probable Higgs decay channel; novel techniques to search for potential new physics using boosted hardonically decaying Higgs boson, and a first search for singly produced long-lived neutral particle that may be realized via Higgs portal.  The talk will mainly focus on general descriptions of the measurements without too much technical details, so that the content is accessible to non experimental particle physicists.

Neutron lifetime with a cold neutron beam at NIST Shannon Fogwell Hoogerheide Presentation at 2:30 PM, NPL 178 Coffee and cookies starting at 2:15 PM

Neutron beta decay is the simplest example of nuclear beta decay and a precise value of the neutron lifetime is important for consistency tests of the Standard Model and Big Bang Nucleosynthesis models. There is currently some disagreement among various measurements of the neutron lifetime, with the results of two experiments using cold neutron beams being higher than several experiments using trapped ultracold neutrons. A new measurement of the neutron lifetime, utilizing the beam method, is underway at the National Institute of Standards and Technology Center for Neutron Research. This measurement is focused on understanding systematic effects in the beam method. An overview of neutron lifetime measurement techniques and current status will be presented. A review of the beam method and the technical improvements in this experiment will be given and the status and outlook of the experiment will be discussed.

The LANL EDM Experiment: Searching for Time Reversal Violation Dr. Thomas Bowles CENPA Conference Room NPL 178

Since CP is violated in Nature, it follows from the CPT Theorem that Time Reversal must also be violated. A finite Electric Dipole Moment of the neutron results from T violation but to date experiments have not observed a finite EDM.

A search for a neutron EDM is underway at Los Alamos using Ultra Cold Neutrons from the solid deuterium UCN source. The experiment is expected to improve the sensitivity to a finite EDM by an order of magnitude over the existing limit.

The talk will discuss the status and plans for the LANL EDM experiment and how the LANL experiment fits with the effort underway (with LANL participation) at the Spallation Neutron Source in Oak Ridge.

Development of He3/He4 Dilution Fridges Prof. Oscar Vilches Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The dilution refrigerator has become the workhorse for experiments in the 5 mK to 1 K range, and provide the starting temperature for nuclear demagnetization and the study of solids and liquids into the 30 nK range. The idea of refrigeration by the dilution of 3He by superfluid 4He was first suggested by Heinz London in 1951, following the proposal by L. Landau and I. Pomeranchuk (1948) that very diluted 3He in superfluid 4He would behave like a gas of quasi-particles.  H. London, G. R. Clarke and E. Mendoza in 1962 in the discussion of measurements they presented of the osmotic pressure of the mixtures included sketches of two possible refrigerator designs that could work. Following their design, the first barely operating refrigerator (0.22K) was built in Leiden in 1965. In 1965-66 continuously operating 0.05K refrigerators were built in Moscow and in Manchester. In 1966 at the U. of Illinois a refrigerator built with improved heat exchangers reached 0.02K, and a single cycle refrigerator precooled by the continuous refrigerator reached 0.0044 K. Why did it take until 1965 to build the first refrigerators? Along the way 3He had to become reasonably available, properties of 3He-4He mixtures had to be studied starting with their vapor pressure, mixing enthalpy, phase separation, and the existence of dilute solutions down to 0.003 K (and theoretically 0 K). In this semi-historical “memoir” I’ll review the steps that led to the Illinois refrigerators and the development of the current commercial ones, including one recently installed in our Department.

The KATRIN neutrino mass experiment Dr. Menglei Sun Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The absolute neutrino mass scale plays an important role in cosmology, particles physics and astrophysics. The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at a direct and model independent determination of the neutrino mass with 0.2 eV (90% C.L.) sensitivity via ultrahigh precision measurements of the kinematics of tritium beta decay. It combines an ultra-luminous molecular windowless tritium source with a high resolution MAC-E-filter based spectrometer. This talk will report the neutrino mass measurement result from the first four-week science run of the KATRIN in spring 2019.

LArIAT: Liquid Argon In A Testbeam Johnny Ho Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The LArIAT (Liquid Argon in a Testbeam) experiment in Fermilab's Test Beam Facility exposes a liquid argon time projection chamber (LArTPC) to a test beam in order to study LArTPC responses to a variety of charged particles.  Event identification and reconstruction techniques as well as cross section measurements from LArIAT will provide critical input to existing liquid argon neutrino experiments such as MicroBooNE, SBND, and ICARUS, and will also help to improve future precision neutrino oscillation measurements in the Deep Underground Neutrino Experiment (DUNE).  This talk will give an overview of the experiment and highlight several recent and upcoming results.

Tests of Fundamental Physics with Atom Interferometry Prof. Saïda Guellati-Khélifa Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Nowadays, light-pulse interferometry with cold atoms has become a powerful tool to test the fundamental laws of physics. I will present briefly the basic concepts of this technique and review the many applications from table-top to large-scale experiments. I will focus on the determination of the fine structure constant from the measurement of the recoil velocity of an atom after the absorption of a photon. I will present the most recent result of the new experiment in Paris and conclude my talk with a discussion of the comparison between the experimental value of the anomalous magnetic moment of the electron and the one predicted by the standard model using this value of the fine structure constant.


The Beam EDM Experiment Dr. Zachary Hodge Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The Beam EDM experiment is a new neutron electric dipole moment search that aims to overcome a limiting systematic of previous beam based measurements. A novel technique using a pulsed neutron source and time-of-flight is employed to account for the velocity dependent effects. The project is currently under development, with several successful tests of a small-scale version using cold neutron beams available at Institut Laue-Langevin and the Paul Scherrer Institute. Ultimately, a full-scale implementation is planned for the upcoming European Spallation Source in Sweden.  This experiment intends to provide a complementary measurement to the widely established use of stored ultra-cold neutrons, with a competitive sensitivity.

Precision Measurements of Neutron Scattering Lengths of Helium Isotopes Using Neutron Interferometery Prof. Fred Wietfeldt CENPA Conference Room NPL-178

The low energy neutron scattering length is an important feature of the neutron-nucleus strong interaction.  Neutron scattering lengths have many applications in neutron science and nuclear engineering. They can also be used to test nucleon potential models and low energy few body effective field theories. A neutron interferometer splits the wave function of a single neutron into two separated coherent paths by Bragg diffraction. The relative phase shift caused by a target in one path produces an interference signal that is measured by a neutron counter. This gives direct and precise access to the neutron scattering length. I will describe measurements of neutron scattering lengths of helium isotopes using the NIST neutron interferometer, including our most recent result for helium-4 which improved its precision by a factor of nine.

Nuclear Physics without High Momentum Potentials: Constructing the Effective Interaction Directly from Scattering Data Prof. Wick Haxton CENPA Conference Room NPL-178
I discuss a rather different approach to effective interactions in which a single step is taken from QCD to a shell-model-like effective space, avoiding the usual construction of an NN potential (and subsequent steps to derive from the potential an interaction appropriate to the shell model).   The scattering data previously used to construct the potential is instead used directly in the shell model. Key to doing this is the use of an energy-dependent interaction — which I will argue is as simple as standard effective interactions — that allows one to construct a theory that is analytically continuous in energy and generates the correct solution at every energy E (despite its use of a finite shell-model space).  The theory also allows one to treat the pion — chiral symmetry — in a much simpler and more physical way than in conventional effective field theories: one keeps the long-range part that one needs, while not introducing fictitious singular behavior at short range.


An Improved Measurement of the Neutron Beta-Neutrino Correlation with the aCORN Experiment Prof. Fred Wietfeldt CENPA Conference Room NPL-178

The decay of the free neutron into a proton, electron, and antineutrino is the simplest beta decay system. The electron-antineutrino correlation (a-coefficient) is one of several important experimental parameters of neutron decay. Together these can be used to determine the weak decay couplings GA and GV, measure the CKM matrix element Vud, and conduct precision low energy tests of physics beyond the Standard Model. The aCORN experiment uses a novel “wishbone asymmetry” method that, unlike previous experiments, does not require detailed proton spectroscopy. The first aCORN run in 2013–2014 produced an improved measurement of the neutron a-coefficient. The second run in 2015–2016 on the high-flux beamline NG-C at the NIST Center for Neutron Research collected a ten-times larger data set and now has a preliminary result. Details and results of the experiment will be presented.

Lattice QCD and its Applications to Nuclear Physics and Fundamental Symmetries Prof. Amy Nicholson (University of North Carolina) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

QCD has been long accepted as the underlying theory behind nuclear forces. However, calculations of nuclear properties directly from QCD have only very recently become mature. The theory's non-perturbative nature at low energies requires the use of lattice regularization (lattice QCD) combined with numerical methods for its solution. With these tools in hand, we are now starting to be able to predict properties of nucleons and their interactions with fully controlled and quantifiable systematics. In addition to giving us unique theoretical insight into the structure of nuclei, these techniques will allow us, for example, to inform the design and construction of experiments which utilize specific nuclei for their symmetry properties, as well as pin down potential signs of new physics from experimental signals. In this talk I will present recent results from the CalLat collaboration relevant for nuclear physics, including a calculation of the nucleon axial charge to sub-percent precision and quantities relevant for neutrinoless double beta decay searches.

CALIOPE, A Search for CPT-Violation in Positronium Dr. Chelsea Bartram, University of Washington Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

We present the results of a search for CPT-violation in the charged lepton sector by studying ortho-positronium decays with CALIOPE, or CPT Aberrant Leptons in Ortho-

Positronium Experiment. Positronium, a bound state of an electron and positron, occurs in both a singlet and triplet state. The triplet state, ortho-positronium, decays primarily into three gamma rays. CPT-violation could potentially manifest itself in angular correlations between the directions of the three photons and the spin of the ortho-positronium (o-Ps). The APEX annular array consists of 24 NaI(Tl) bars arranged cylindrically and provides 75% angular coverage with a source placed at its center. We used the APEX array at Triangle Universities Nuclear Laboratory (TUNL) to acquire data for CALIOPE continuously for several months. We present the results of 16 weeks of data-taking, in addition to a comprehensive systematics study. We suggest improvements that would make such a search competitive with the most sensitive CPT-violation searches in o-Ps performed to date and discuss the possibility of a search for CP-violation.

Searching for the WIMP Modulation with the COSINE-100 Dark Matter Experiment Dr. Walter Pettus, University of Washington Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM
Cosmic observations indicate that the dark matter component of our universe is more than five times as abundant as ordinary matter. The halo of dark matter surrounding our own galaxy and streaming past Earth presents a source of these particles to study in terrestrial experiments with distinctive signal features. Within the field of experiments searching for WIMPs, a theoretical favored dark matter candidate, no definitive signals have been detected with only one exception. The DAMA experiments operating arrays of low-background sodium iodide claim a persistent, high-significance (>9 sigma), model-independent detection of dark via its annual modulation signature. For twenty years that claim has stood, now in significant tension with many other experiments, but no one has been able to execute a complete test of the same signal with the same target material. I will present the COSINE-100 experiment, which has been operating a low-background array of NaI(Tl) crystals at Yangyang Underground Laboratory in South Korea since 2016. Our recent results already contradict the standard dark matter interpretation of the DAMA signal and are building to the final model-independent test. A decades-old mystery finally stands to come unravelled.


Sustained Neutron Production from a Sheared-Flow Stabilized Z Pinch Dr. Yue Zhang, University of Washington Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM
The Z-pinch is a type of plasma confinement system that uses an electrical current in the plasma to generate a magnetic field that compresses it. However, the realization of high-performance Z-pinch plasmas is severely limited by classical magnetohydrodynamic (MHD) instabilities. Recently the UW-LLNL collaborative project, FuZE (Fusion Z-pinch Experiment) has demonstrated that sheared plasma flows can be used as a stabilization mechanism to achieve and sustain fusion-relevant plasmas in Z-pinch configurations. The stabilization is effective even when the pinch current is sufficiently high to compress the plasma column to small radii (3 mm), producing increases in magnetic field (8.5 T), fusion-relevant plasma density (2e17 /cc) and electron temperature (1 keV). Sustained fusion neutrons are observed during an extended time period (up to 8 microseconds) from a 50-cm long stable Z-pinch plasma that is generated with a deuterium and hydrogen gas mixture. The neutron production is not associated with MHD instabilities, scales with the square of the deuterium concentration, and agrees with the thermonuclear yield calculated from the measured plasma parameters, all of which indicate consistency with a thermonuclear fusion process with no measurable beam-target component. This presentation will touch on the historical development of the sheared-flow-stabilized Z pinch at the University of Washington and discuss the experimental results in detail.
Eric Machado - General Exam Project 8: Neutrino Mass and Tales of a Convoluted Beta Spectrum CENPA Conference Room NPL-178
Constraining the conditions for r-process nucleosynthesis via nuclear measurements at CARIBU Prof. Guy Savard, PhD Presentation at 2:30 PM, NPL 178 Coffee and cookies starting at 2:15 PM

The r-process, a series of rapid neutron-capture reactions in cataclysmic astrophysical events such as neutron star mergers, is responsible for the creation of roughly half of the heavy nuclei in our universe. The conditions present in these events are such that neutron-capture reactions occur on a time scale much shorter than the lifetime of the nuclei involved and the process therefore proceeds mainly through reactions on short-lived very neutron-rich nuclei, most of which never observed in the laboratory. Sensitivity studies have looked at various scenarios for the r-process conditions and identified nuclei whose basic properties would have the largest impact on the distribution of produced nuclei. At ANL, a program centered around the ATLAS facility is aimed at improving access to these nuclei and has developed tools to measure the most critical quantities to constrain r-process scenarios.

The talk will discuss the basic nuclear physics inputs required to understand the r-process and will present the CARIBU upgrade of ATLAS that is now providing access to some key nuclei along the r-process path. Recent measurements on nuclei around the N=82 and rare-earth r-process abundance peaks, focusing on Penning trap mass measurements on very exotic isotopes, will be discussed. A new approach recently implemented to increase the sensitivity of these mass measurements will also be presented.


Revealing Condensate Structures in Axion Dark Matter Halos Erik Lentz, PhD (University of Gottingen) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM
Axions and axion-like particles are becoming increasingly attractive candidates for the dark matter. Likewise, searches for these candidates are increasing in sophistication, number, reach, and may span much of the candidates' viable parameter space in the next decade. Axion cavity searches like ADMX at UW are capable of extracting detailed knowledge of the local axion distribution, and may tell us a great deal about the formation of our own galaxy. Our understanding of axion structure formation is far from complete, however, due largely to the candidate’s unique properties as a highly degenerate Bose fluid. I present in this talk a new model of structure formation for the well-motivated QCD axion which respects these properties. Theory and preliminary simulations show notable structural deviations from standard cold dark matter models due to exchange-correlation interactions. Implications for an ADMX-like experiment are presented.
From yeV to TeV: Measurement and Interpretation of the Neutron EDM Prof. Doug Beck, PhD Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The neutron's electric dipole moment (EDM) has been a subject of interest at least since the late 1940's when the general question of whether, for example, the strong force was invariant under a parity transformation.  This led to the first measurement using a modified nuclear magnetic resonance technique that is still used, in one form or another, to measure the neutron EDM.  Today, the physics questions are associated with the time reversal violation implied by the existence of a neutron EDM.  In this talk, I will focus on a few of the modified techniques used in experiments at ORNL and the ILL, both in the assembly stage, to push the measurement sensitivity an order of magnitude (or two) below the current limit.

Defining the proton radius: A unified treatment Prof. Gerald Miller University of Washington Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Background: There is significant current interest in knowing the value of the proton radius and also its proper definition.

Purpose: Combine the disparate literatures of hydrogen spectroscopy and diverse modern parton distributions to understand the meaning of the proton radius in a manner consistent with the separate bodies of work. Methods: Use perturbation theory, light-front dynamics, and elementary techniques to find relativistically correct definitions of the proton radius and charge density.

Results: It is found that the very same proton radius is accessed by measurements of hydrogen spectroscopy and elastic lepton scattering. The derivation of the mean-square radius as a moment of a spherically symmetric three-dimensional density is shown to be incorrect. A relativistically correct, two-dimensional charge density is related to the diverse modern literature of various parton distributions. Relativistically invariant moments thereof are derived in a new relativistic moment expansion, the RME.

Conclusion: The equation r2p≡−6G′E(0) is the definition of the proton radius.

Beta-Delayed Charged Particle Measurements for Studies of Novae and X-ray Bursts Moshe Friedman, PhD (Michigan State University) Presentation at 2:30 PM, NPL 178 Coffee and cookies starting at 2:15 PM

Classical novae and type I X-ray bursts are energetic and common thermonuclear astrophysical explosions. However, our ability to understand these events is limited by the lack of comprehensive nuclear data on proton-rich nuclei. Specifically, constraining the 30P(p,γ)31S and 15O(α,γ)19Ne reaction rates has been found to be crucial to the understanding of nucleosynthesis and energy generation in these events. As direct measurements of these reactions are not technically feasible at the present time, indirect measurements of dominant resonance strengths by β-delayed protons and α particles are used.


A previous measurement at NSCL identified a new 31S state at Ex = 6390 keV to be a key resonance for 30P proton capture at peak nova temperatures. A significant feeding of 3.38% from 31Cl B+ decay was observed, which enables the determination of the resonance strength by measuring the corresponding 259 keV B+-delayed protons. Similarly, a previous measurement at NSCL observed a 0.0156% feeding of the 19Ne state at 4034 keV, a key resonance for the 15O(α,γ)19Ne reaction, by the 20Mg(B+p) sequence. This feeding is sufficient to determine the resonance strength by measurement of the proton-α pairs.


A gas-filled detector of Beta-delayed charged particles has been designed and built to measure the aforementioned decays at NSCL. The detector is coupled with the Segmented Germanium Array (SeGA) to enable coincidence γ-ray detection as an additional probe of the decay scheme and for normalization purposes. The first phase of the detector functions as a proton calorimeter, was successfully commissioned with 25Si(B+p)24Mg, and used to measure several decays of interest including 31Cl. We will report on the performance of the detector and present preliminary results. We will also discuss the upgrade of the detector into a TPC for the measurements of the 20Mg(B+pα) sequence.

Below the Waterline: How Every One of Us Can Contribute to Positive Culture Change to Reduce Sexual Harassment Prof. Sharona Gordon, PhD (University of Washington) Coffee and cookies starting at 3:00 PM Presentation at 3:15 PM, NPL 178 Followed by questions and discussion

The presentation will provide an overview of the NASEM report and present strategies to prevent Sexual Harassment that can be implemented by students, faculty, and staff without direct administrative support. Improving academic culture from the bottom up is novel, in part due to the transitory nature of students and other trainees on campuses. Because academic administrators have traditionally set the priorities and determined the strategies used to change the course of their institutions, faculty and staff have not generally felt empowered to initiate and lead transformative programs. The NASEM report on Sexual Harassment discusses why faculty, students, and staff should step in, “Placing responsibility and control for Sexual Harassment planning and response at the highest administrative level guided by attorneys... would likely produce a different organizational culture and climate than one guided by a more transparent group of faculty, students, and service providers...” Strategies presented include: identifying and addressing local problems; building community; reimagining mentoring; and supporting targets of harassment.

KATRIN: Sprinting Toward Neutrino Mass Prof. Diana Parno, PhD (Carnegie Mellon University) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

After many years of painstaking design, construction, and commissioning work, the Karlsruhe Tritium Neutrino experiment (KATRIN) is poised to
begin taking neutrino-mass data this month. I will give a brief highlights tour of the recent commissioning campaigns that have helped us characterize and gain confidence in our apparatus, before sharing some of the remaining puzzle pieces that must be finalized for our first neutrino-mass result. I will discuss a few novel background sources, strategies for spectral fits, and a selection of systematic effects. These considerations will guide us in shaping KATRIN's future.

Search for Vector Boson Scattering with W/Z boson jet at ATLAS Tatsumi Natta, PhD Waseda University (Japan) Cookies and Coffee starting at 3:30pm; Presentation at 3:45pm
Vector boson scattering (VBS) is a key process to probe the electroweak symmetry breaking (EWSB) of the Standard Model, since it involves both self-couplings of the vector bosons and the coupling with Higgs boson. If the Higgs mechanism is not the sole source of EWSB, the scattering amplitude deviates from SM prediction at high scattering energy.  Moreover, deviation may be detectable even if a new physics scale is higher than reach of direct search. The LHC-ATLAS experiment have been finished 3 years Run2 physics program at √s = 13 TeV. In this talk, I will present recent study of VBS at Run2 focussing on final states having boosted W/Z jets. The boosted W/Z jets tagging is one of key techniques to probe the most energetic scatting W/Z boson in the VBS process. The recent development of boson tagging techniques is also presented.
Nuclear reactor and astrophysics neutrinos with the JUNO experiement Mariangela Settimo, PhD SUBATECH CNRS (France) Presentation at 3:45pm Coffee and Cookies starting at 3:30pm
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator underground detector, under construction in China. The main goal of the experiment is the neutrino mass hierarchy determination and the high-precision neutrino oscillation parameter measurements, detecting electron anti-neutrinos emitted from two nearby (baseline of about 53 km) nuclear power plants. JUNO experiment is not only a reactor neutrino experiment for the mass hierarchy and oscillation, but also for supernova and astrophysics studies. In this seminar, I will briefly presents the physics perspectives and give a status of its construction.
Results from sub-GeV dark matter searches and high voltage breakdown studies in liquid argon and xenon Lucie Tvrznikova, Phd (Lawrence Livermore National Laboratory) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Sub-GeV WIMP dark matter (DM) is usually difficult to probe using liquid xenon
detectors due to a small energy transfer in DM-nucleus interactions and a finite
detector threshold. However, two novel direct detection methods overcome this
limitation: the Bremsstrahlung and Migdal effects allow us to consider electron recoils
that accompany the standard DM-nucleus scattering, thereby extending the reach to
lower DM masses. I will present constraints on DM-nucleon scattering using data
acquired in 2013 by the Large Underground Xenon (LUX) experiment. Looking ahead,
the increasingly large noble liquid detectors are facing challenges with applications of
high voltage (HV). The Xenon Breakdown Apparatus (XeBrA) at the Lawrence Berkeley
National Laboratory was built to characterize the HV behavior of liquid xenon and liquid
argon. Results from XeBrA serve not only to improve our understanding of the physical
processes involved in the breakdown but also to inform the future of noble liquid
detector engineering and neutrinoless double beta decay searches.

Quantum computing for nuclear physics: status and expectations Natalie Klco (Institute for Nuclear Theory, UW, Seattle) Presentation at 2:45 PM, NPL 178 Coffee and cookies starting at 2:15 PM

Studying nature directly from quark and gluon degrees of freedom is often
computationally limited by nature's physical characteristics of exponentially growing
Hilbert spaces with particle number and sign/signal-to-noise problems. As a result,
Minkowski-space dynamics and fermionic many-body structure calculations require
exponentially large classical computing resources to provide results with necessary
precision. This leaves many systems of interest to nuclear and particle physics (finite
density systems, fragmentation functions, non-equilibrium systems etc.) intractable for
known algorithms with current and foreseeable classical computational resources.
Fortunately, there are good reasons to expect that it will be efficient to simulate
locally-interacting quantum systems with quantum systems. By leveraging their natural
capacity to represent wavefunctions and directly manipulate amplitudes rather than
probabilities, the use of quantum systems as a computational framework leads to
constructions of basic quantum field theories with resource requirements that scale
only polynomially with the precision and size of the system. In this talk, I will present an
overview of recent efforts in, and the potential for, quantum computing to address
important aspects of quantum field theories relevant to nuclear physic

Search for New Physics with Neutrinoless Double-β Decay The Ge-76 Experimental Program Dr. Matteo Agostini (Technische Universität München, Germany) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at ​ 3:30 PM

The neutrinoless double-β decay is a hypothetical nuclear
transition predicted by most of the theories that explain the origin
of neutrino masses or the dominance of matter over antimatter in
our Universe. Its discovery would unambiguously prove that the
lepton number is not conserved and neutrinos are their own
antiparticles. The experimental search for the neutrinoless
double-β decay is a very active and rapidly growing field, with
several experiments running and many others under preparation.
The talk will cover the theoretical and experimental aspects
connected to the neutrinoless double-β decay, with focus on the
experimental program based on Ge-76.

Atomic parity violation and searching for dark matter with magnetic resonance: recent results from Mainz Prof. Dr. Dimitry Budker (Johannes Gutenberg-Universität Mainz, Germany) Presentation at 10:30 AM, NPL 178 Coffee and cookies starting at 10:15 AM

We will discuss a measurement of atomic parity violation in a
chain of Yb isotopes and the progress in the CASPEr
experiments, including the recent results of the search for
ultralight dark-matter fields with zero- and ultralow-field (ZULF)
nuclear magnetic resonance.

The Compact Binary Census after LIGO/Virgo's Second Observing Run Prof. Ben Farr, PhD (University of Oregon, Eugene) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

With 5.9 binary black hole mergers and 1 binary neutron star merger announced so far, the Advanced LIGO and Virgo detectors have started their census of the local(ish) compact binary population. With detection rates as high as one per week in the next observing run, and one per day in the coming years, we will quickly accumulate the statistics necessary to constrain the physics relevant to binary formation. I will present some the techniques being developed to make these inferences, what we have learned so far, and what we might learn in the near future.

Hadronic corrections to the anomalous magnetic moment of the muon Dr. Peter Stoffer, University of California, San Diego INT Conference room C421

The anomalous magnetic moment of the muon g-2 has been measured and computed to very high precision of about 0.5 ppm. For more than a decade, a discrepancy has persisted between experiment and Standard Model prediction, now of about 3-4 sigma. The main uncertainty of the theory prediction is due to strong-interaction effects, the hadronic vacuum polarisation (HVP) and hadronic light-by-light (HLbL) contributions.

While the most precise HVP evaluation is based on dispersion relations and data input, HLbL is currently plagued by uncontrolled model uncertainties. Within a dispersive framework based on unitarity and analyticity, we scrutinize the uncertainty estimates for the two-pion HVP channel and we calculate model-independently two-pion contributions in HLbL, which shows an avenue towards a data-driven evaluation of g-2 of the muon.

Prospects for laboratory searches for Planck-scale Dark Matter William Terrano, PhD (Technische Universität München, München, Germany) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

will discuss the tantalizing prospect that Dark Matter is a
relic of physics at the Planck-scale, where quantum gravity
effects are expected to become important. I will review
how physics at such high energy scales can produce
low-energy relics and describe the properties of Dark
Matter if it is in fact such a relic. I’ll then look at whether
there is any hope for a laboratory detection of Planck-scale
Dark Matter through its spin-couplings, taking advantage of
the recent great strides — thanks to medical physics
applications — in producing large quantities of
coherently-polarized nucleons.

Status of the Mu3e experiment Dr. Frederik Wauters (Johannes Gutenberg-Universität, Mainz, Germany) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The upcoming Mu3e experiment searches for the lepton
flavour violating decay μ + →e + e e + aiming for a final single
event sensitivity of 1 x 10 -16 . We are currently finalizing the
design of the first phase, which will have single event
sensitivity of 2 x 10 -15 , which will exploit the current muon
rates available at the Paul Scherrer Institute. The Mu3e
detector consist of 4 layers of ultra-thin silicon pixels
developed for this experiment, combined with scintillating
fibers and tile timing detectors to deal with the high decay
rates. Current prototypes meet all requirements, and the
project is moving from the R&D phase to construction.

Short-Range Correlations in nuclei Erez O. Cohen (School of Physics and Astronomy, Tel Aviv University, Israel) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Short-range correlated (SRC) nucleon pairs are a vital part
of the nucleus, accounting for almost all nucleons with
momentum greater than the Fermi momentum (k​F​ ). A
fundamental characteristic of SRC pairs is having large
relative momenta, and smaller center-of-mass momenta as
compared to k​F​ . Knowledge of the c.m. momentum is
essential for understanding the formation mechanism of
SRC pairs. I will report on the extraction of SRC c.m.
motion from measurements of the A(e,e’pp) reaction at
Jefferson Lab.

The Standard Model and Beyond through β-decay Leendert Hayen (Katholieke Universiteit Leuven, Belgium) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The study of nuclear beta decay has guided our physical
understanding of the universe throughout most of the 20​ th century,
directly leading to the unification of electromagnetic and weak
forces and the Standard Model. With new physics seemingly out of
reach with modern colliders, low energy searches for Beyond
Standard Model physics become even more valuable,
consolidating the role of nuclear beta decay as physics moves
forward. With experiments breaking new ground, we will review the
theoretical progress on the beta spectrum shape and frame its role
in ongoing and future tests of exotic currents in the weak
interaction. We will analyze its position in the so-called reactor
antineutrino anomaly which points towards the existence of a
fourth, sterile neutrino. In doing so, we illustrate the influence of
nuclear structure in the outstanding problems and conclusions.

qBOUNCE, a Quantum Bouncing Ball Gravity Spectrometer Prof. Dr. Hartmut Abele (Atominstitut – TU Wien, Austria) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

This talk focuses on the control and understanding of a
gravitationally interacting elementary quantum system
using the techniques of resonance spectroscopy. It offers a
new way of looking at gravitation at short distances based
on quantum interference. The ultra-cold neutron reflects
from a mirror in well-defined quantum states in the gravity
potential of the earth allowing the application of gravity
resonance spectroscopy (GRS). GRS relies on frequency
measurements, which provide a spectacular sensitivity.

Trapped Atoms and Ions for Tests of the Charged Electroweak Interaction Prof. Dan Melconian, PhD (Cyclotron Institute/Dept of Physics & Astronomy, Texas A&M University) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Nuclear decay has a long-standing history of shaping and testing the standard model of particle
physics, and it continues to this day with elegant, ultra-precise low-energy nuclear measurements.
Experiments observing the angular correlations between the electron, neutrino and recoil
momenta following the decay of (un)polarized nuclei can be used to search for exotic currents
contributing to the dominant V−A structure of the weak interaction. Precision measurements of
the correlation parameters to < 0.1% would be sensitive to (or meaningfully constrain) new
physics, complementing other searches at large-scale facilities like the LHC. Ion and atom traps
provide an ideal source of very cold, short-lived radioactive nuclei in an extremely clean and open
environment. As such, they are invaluable tools for precision measurements of β-decay
parameters. This talk will focus on two such efforts. The TAMUTRAP facility at the Cyclotron
Institute, Texas A&M University, will utilize an upgrade to the recently commissioned cylindrical
Penning trap – already the world’s largest with an inner diameter of 90 mm – to search for scalar
currents via the β-ν-correlation in the β-delayed proton decay of T = 2 nuclei. The other effort,
based at TRIUMF in Vancouver, Canada, utilizes neutral atom-trapping techniques with optical
pumping methods to highly polarize (> 99%) 37
K atoms. Recently, we determined the asymmetry
parameter, A​ β​ , to 0.3% precision, which is comparable to or better than any other nuclear
measurement, including the neutron.

On the new MiniBooNE/LSND results Gerry Garvey, PhD (University of Washington) Presentation at 3:00 PM, NPL 178 Coffee and cookies starting at 2:45 PM

I will present and provide some background for a recent
MiniBooNE/LSND posting on the arXiv (1805.12028). The
MiniBooNE result includes new recently analyzed data. The
excess of electron neutrino like events observed in both
MiniBooNE and LSND appears consistent. If interpreted as
muon-neutrino (muon-anti-neutrino) oscillating into electron-
neutrino (electron-anti-neutrino) via a light sterile neutrino, the
best fit has a probability of ~20% while a background only fit
has a ?2 probability of 5x10-7 relative to the best fit. I will also
present a recent update of an arXiv posting by the MINOS
collaboration (1710-06488v2) that would make an
interpretation employing a sterile neutrino highly unlikely.

Cosmic Rays from 10^15 to 10^20 eV Gordon Thomson, PhD (University of Utah) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The energy range covered by the Telescope Array
experiment, from 2x1015 eV to 2x1020 eV, contains the
end of the galactic cosmic ray spectrum, the
galactic-extragalactic transition, important information
about the nature of cosmic rays throughout this energy
region, and what probably are the highest energy
particles in the universe. As time permits, I will discuss
measurements of the spectrum and composition of
cosmic rays, and searches for anisotropy (and hence the
sources of these particles).

Searches for supersymmetry in final states with photons in CMS Menglei Sun (Carnegie Mellon University) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The Standard Model (SM) is very successful at explaining a wide
range of phenomena. With the discovery of the Higgs boson,
the SM is complete. Yet there are still many questions left
unanswered: Why is the Higgs mass so light when it receives
radiative corrections up to the Planck scale? What is dark
matter? The supersymmetric extension to the SM would
provide solutions to these problems. Models of supersymmetry
with general gauge-mediated supersymmetry breaking often
lead to final states containing photons and large missing
transverse momentum. In this talk, I will discuss the searches
for supersymmetry in events with photons in proton-proton
collisions at √S = 13 TeV at the CMS experiment.

First Search for Neutrinoless Double Beta Decay in 76Ge with the Majorana Demonstrator Walter Pettus, PhD (University of Washington) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Neutrinoless double-beta decay (0νββ) is a hypothetical
lepton-number violating process that would establish the Majorana
nature of neutrinos and serve as an indirect probe of the absolute
neutrino mass. The Majorana Demonstrator is an array of high purity
Ge detectors at the 4850’ level of the Sanford Underground Research
Facility in South Dakota searching for 0νββ in 76 Ge. The experiment
consists of two modules totaling 44 kg of p-type point contact
detectors; the first module began data taking in June 2015, with the
entire array operational since August 2016. I will report the analysis
of the first 9.95 kg*yr of exposure from the MAJORANA
DEMONSTRATOR, achieving a half-life limit of >1.9×10 25 yr for 0νββ
decay of 76 Ge. The experiment has also demonstrated the best
energy resolution and a background consistent with the best
achieved of any 0νββ experiment. These results strongly position
76 Ge for a future tonne-scale 0νββ experiment.

First Results from ADMX G2 Prof. Gray Rybka, PhD (University of Washington) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The axion is a well-motivated dark matter candidate inspired by
the Peccei-Quinn solution to the Strong-CP problem. After
decades of work, the US DOE flagship axion dark matter search,
ADMX G2, is the first experiment to be sensitive to dark matter
axions from the plausible DFSZ coupling model, and has begun
to search the theoretically-favored axion mass region 2-40
micro-eV. ADMX G2 could now discover dark matter at any
time. I will report the first results from exploring the range
around 2.7 micro-eV last year, discuss this year's operations
and review the ADMX G2 plans to continue the search to cover
the entire mass range.

Key Technology Research of Liquid Argon Veto Detector in CDEX Qinghao Chen (Tsinghua University, Beijing, China) Remote seminar presentation starting at 3:45 PM in NPL 178 Coffee and cookies starting at 3:30 PM

The China Dark Matter Experiment (CDEX) Collaboration has been aiming to search for low mass
WIMPs with a ton-scale highly pure germanium (HPGe) detector. In order to suppress the
background, an anti-coincidence veto detector is employed in CDEX, acting as the active shielding.
However, active shielding system with solid scintillators has to be abandoned as the Ge detector get
larger in the following phases of CDEX experiments. The Liquid Argon (LAr) veto is proposed in the
second phase CDEX-10 which is the first dark matter direct detection experiment using LAr detector
as an anti-coincidence veto detector. My research work is focused on the R&D of CDEX-10 LAr veto
detector, which contains:
(1) Designing and building a prototype of the liquid argon detector. The principle of the LAr detector
experiment and the operating processes have been mastered. The methods of data analysis have
been developed. All of these will help to the operation of the CDEX-10 LAr veto detector.
(2) Measurement and the Monte Carlo simulation of the photoelectron yield of the prototype LAr
detector. The photoelectron yields of the prototype LAr detector have been measured to be
0.051-0.079 p.e./keV for 662 keV γ lines at different positions. The Monte Carlo simulation provided
a better understanding of the spectra we obtained.
(3) Research of pulse shape of the LAr scintillation lights. The pulse shape discrimination of γ
particles and α particles has been studied. The prompt fraction Fprompt was found to be different
between the γ particles and α particles, which provides the possibility to develop the pulse shape
discrimination method of the LAr detector which is unpurified. In addition, the relationship between
the slow component lifetime of Ar scintillation lights and the Ar purity has also been studied. The
purity of LAr can be monitored through this method.
(4) The performance of the CDEX-10 LAr veto detector has been estimated by Monte Carlo
simulation. The energy threshold and the veto efficiency of the LAr veto detector was got through
simulation. The background of CDEX-10 was simulated to be < 0.1 cpkkd after the active shielding
of the LAr veto detector.

Exploring Neutrino and Axion Physics with the Majorana Demonstrator Clint Wiseman (University of South Carolina) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The MAJORANA DEMONSTRATOR is an array of P-type point contact
germanium detectors enclosed in a low-background shield, operating at
the Sanford Underground Research Facility. The first results from its
search for neutrinoless double beta decay with a 10 kg-y data set show
world-leading energy resolution at the Q-value (2039 keV) and extremely
low background levels in its optimal configuration. This is an important
milestone in the development of a next-generation, ton-scale experiment.
Complementary to its neutrino program, the DEMONSTRATOR is also
capable of low energy rare event searches, routinely operating with
sub-keV thresholds. This is enabling a search for dark matter and solar
axions. The lowest energy regions of the data set present a challenge to
reliably discriminate physics from electronics noise.
In addition to a discussion of the recent double-beta decay result, I will
discuss new noise rejection methods for the DEMONSTRATOR and
prospects for an upcoming solar axion result.

Alpha-Related Backgrounds in the DarkSide-50 Detector Alissa Monte (University of Massachusetts, Amherst) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

DarkSide-50 is the current phase of the DarkSide direct dark matter
search program, operating underground at the Laboratori Nazionali
del Gran Sasso in Italy. The detector is a dual-phase argon Time
Projection Chamber (TPC), designed for direct detection of Weakly
Interacting Massive Particles (WIMPs), and housed within a veto
system of liquid scintillator and water Cherenkov detectors. Since
switching to a target of low radioactivity argon extracted from
underground sources in April 2015, the background is no longer
dominated by naturally occurring Ar-39. However, alpha backgrounds
from radon and its daughters remain, both from the liquid argon bulk
and internal detector surfaces. This talk will focus on the analysis of
alpha events in DarkSide-50. In some cases, the alpha events are a
dangerous background in need of mitigation. In others, the alpha
events can be used as a tool to deepen our understanding of our

Recent High Mass WIMP search results from DarkSide-50 Xin Xiang (Princeton University) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Located at the LNGS, Italy, DarkSide (DS) is a dark matter search
project, which features a dual-phase Time Projection Chamber
as the WIMP detector, surrounded by an organic
liquid-scintillator neutron veto and a water-Cherenkov muon
veto. The current DS-50 has been taking data with Ar extracted
from underground sources (UAr) since April 2015. As of October
2017, the experiment accumulated 532.4 live-days exposure of
blinded data with the UAr target. In this talk, I will present the
recent blind analysis and the spin-independent dark
matter-nucleon coupling results. Various background studies will
be discussed, with an emphasis on a novel concept of
Cherenkov coincidence background. The Monte Carlo modeling
of the background predictions will be presented .

Towards reliable nuclear matrix elements for neutrinoless double-beta decay Prof. Javier Menéndez (The University of Tokyo, Japan) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Observing neutrinoless double-beta (0nbb) decay is the most promising
way to detect lepton number violation in the laboratory, and it would imply
that neutrinos are its own antiparticle. The decay half-life naturally
depends on a nuclear matrix element that needs to be calculated
theoretically. A good knowledge of this matrix element is key for the
planning of 0nbb decay experiments, and also to extract information on
the neutrino mass once 0nbb decay is observed.
At the moment, predicted matrix-element values depend on the
many-body method used to calculate them and, in addition, they may
need to be ”quenched”, as the matrix elements of other beta decays that,
however, have a very different momentum-transfer regime. I will discuss
recent efforts towards obtaining reliable nuclear matrix elements, ranging
from improved calculations with standard many-body approaches, to the
first application of "ab initio" many-body methods to 0nbb decay, finalizing
with possible measurements that could be very useful to test calculations
and to constrain the value of the 0nbb matrix elements.

What Stubs and Sparkles In Vast Vats of Liquid Will Tell Us About Exploding Stars Kate Scholberg (Duke University) PAA A-102

When a massive star collapses at the end of its life, nearly all of the gravitational binding energy of the resulting remnant is released in the form of neutrinos. I will discuss the nature of the core-collapse neutrino burst and what we can learn about particle physics and about astrophysics from the detection of these neutrinos. I will cover supernova neutrino detection techniques in general, current supernova neutrino detectors, and prospects for specific future experiments. ​

Beta decay with atom traps John Behr, PhD (TRIUMF) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

We've recently measured a beta decay asymmetry with respect to the nuclear spin with the best fractional accuracy achieved in nuclei or the neutron. This increases the sensitivity of an unusual conserved vector current test in nuclei previously explored at our lab, and constrains standard model extensions that restore parity symmetry.  I'll describe this and other future plans with TRIUMF's neutral atom trap experiment, including a measurement of the neutrino energy spectrum of the 0- to 0+ decay of a reactor fission product, a time-reversal violation test in radiative beta decay, and possible isospin mixing tests using the nuclear progeny asymmetry with respect to the initial spin.

Spin-Momentum Correlations, Aharonov-Bohm, and Color Entanglement in Quantum Chromodynamics Prof. Christine A. Aidala, PhD (University of Michigan) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

After the development of QCD in the last quarter of the 20th century, we are now in the early years of an exciting new era in which much more quantitative QCD calculations can be tested against increasingly sophisticated experimental measurements. Advances include a greater focus on the dynamics of quarks and gluons within bound states and in the process of bound-state formation. Over the last decade and a half, studies initially focused on spin-momentum correlations in the proton have brought to the fore several deep, fundamental issues within QCD. We are now exploring the physical consequences of gauge invariance in QCD as a quantum field theory, analogous to the Aharonov-Bohm effects familiar to many from QED but predicted for any gauge-invariant quantum field theory. Given the unique non-Abelian nature of the QCD gauge group, these quantum mechanical phase effects lead to an exciting novel prediction of entanglement of quarks and gluons across QCD bound states. Recent results from the PHENIX experiment at the Relativistic Heavy Ion Collider will be highlighted.

PROBING DARK MATTER WITH Axion Dark Matter eXperiment (ADMX) Dr. Rakshya Khatiwada (University of Washington) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The Axion Dark Matter eXperiment (ADMX) is one of the three DOE “Generation-2” direct dark matter searches and the only one dedicated to finding the QCD axion. If discovered, the axion not only solves the strong CP problem but also shines light in the cold dark matter content of the universe. ADMX set a new record as the first ever axion experiment to reach the DFSZ sensitivity with its new results from 2017. This talk will focus on the recent upgrades in the dilution refrigerator operating at 90mK, the state-of-the-art quantum electronics and new techniques used to obtain these results followed by a discussion on the future of ADMX.

Fundamental Neutron Physics at the Institut Laue-Langevin Dr. Peter Geltenbort (Institut Laue-Langevin, Grenoble, France) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The Institut Laue-Langevin (ILL) is an international research center at the leading edge of neutron science and technology. As the world’s flagship center for neutron science, the ILL provides scientists with a very high flux of neutrons feeding some 40 state-of-the-art instruments, which are constantly being developed and upgraded. The instruments of the nuclear and particle physics group (NPP) and their fields of research are briefly presented.
ILL’s two ultracold neutron installations are described in more detail. The ongoing research program using ultracold neutrons as measuring the lifetime of the free neutron, the search for an electric dipole moment and gravity resonance spectroscopy are highlighted.

The Proton Radius Old Measurements and New Ideas Prof. Guy Ron (Hebrew University of Jerusalem, Israel -- George Washington University, Washington DC) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

The radius of the proton, generally assumed to be a well measured and understood quantity has recently come under scrutiny due to highly precise, yet conflicting, experimental results. These new results have generated a host of interpretations, none of which are completely satisfactory. I will discuss the existing results, focusing on the discrepancy between the various extractions. I will briefly discuss some theoretical attempts at resolution and focus on new scattering measurements, both planned and already underway, that are attempting to resolve the puzzle.

Report from the International Conference on Women in Physics Dr. Laura Gladstone (Case Western Reserve University, Ohio) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

In July 2017, I was one of the US delegates to the IoP International Conference on Women in Physics, held in Birmingham, UK. The conference brought together feminist scientists from around the world to share their work and inspiration, to mentor each other, and to share best practices. Each country's delegation summarized the status and main obstacles for women physicists in their country. In this talk, I will explain the issues presented in the US country poster: implicit bias, stereotype threat, and intersectionality with other marginalized identities. For each, I will briefly touch on some best practices for creating an equitable work environment from several professional levels. I will also summarize the findings of the 5 workshops and select foreign country posters.

Lepton flavors: high-intensity probes of new physics Dr. Ana Teixeira (Laboratoire de Physique de Clermont, France) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Massive neutrinos and leptonic mixings have provided the first evidence of flavor violation in the lepton sector, opening a unique gateway to many new phenomena, with an impact ranging from low-energy observables to colliders, as well as cosmology and astroparticle physics. If observed, charged lepton flavor violation (cLFV) is a clear sign of New Physics - beyond the Standard Mode (SM) minimally extended to accommodate neutrino oscillation data. We begin by a brief overview of the experimental status of cLFV (and other high-intensity observables) searches and the prospects for upcoming years. We then consider extensions of the SM which could potentially give rise to observable cLFV signals: following a model-independent discussion, we comment on the prospects of several New Physics models regarding cLFV, with a particular emphasis on low-energy seesaw mechanisms.

Microscopic uncertainties in the standard solar model Prof. Doron Gazit - Racah Institute of Physics (Hebrew University of Jerusalem, Isreal) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Over the past decade, an outstanding open problem in solar physics has emerged, as solar photospheric abundances of metallic elements have been significantly revised downward. Standard solar models cannot reproduce helioseismic measurements, such as the convection zone radius, the surface helium abundance and the sound speed profile, when using these revised abundances. This gave rise to the solar composition problem, motivating a rapid growth of research efforts in the field. With this problem of in mind, I study two main microscopic phenomena occurring in the Solar interior, and discuss their theoretical uncertainties and ways to reduce them. Firstly, the fusion rate of two protons into a deuteron, which is too rare to measure terrestrially in the solar conditions, is studied using a novel application of pion-less effective field theory.
Secondly, I use a new atomic code “STAR" to study two major plasma effects on the solar profile, namely ionic correlations and line broadening. These effects are untested in the relevant thermodynamic conditions, and use crude approximations, whose applicability at this regime is unclear. Both microscopic phenomena have a significant effect on the solar problem. Moreover, we argue that the solar opacity problem is hindered due to the large uncertainties. In the case of the atomic effects, we propose a method to measure opacities at solar temperatures and densities that were never reached in the past via laboratory radiation flow experiments.

The Quest for a Background-Free Detector Daniel Baxter (Northwestern University) CENPA Conference Room NPL-178

Dark matter represents one of the most sought after discoveries in physics. Leading theories predict that extremely sensitive detectors could probe nuclear recoils from dark matter interactions. The PICO collaboration uses bubble chambers to look for the energy deposition from such an interaction. The biggest challenge in searching for dark matter is the mitigation and understanding of the numerous other sources of events that could look like dark matter, namely radioactive backgrounds. I will discuss how a long effort to understand backgrounds in the PICO bubble chambers led to the recent background-free result of PICO-60 and how discoveries made along the way might affect other rare event searches.

First observation of coherent elastic neutrino-nuclear scattering with COHERENT Prof. Jason Detwiler, PhD (University of Washington) Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Coherent elastic neutrino-nuclear scattering (CEνNS), the most frequent of all low-energy neutrino interactions, was predicted over forty years ago, but had eluded observation due to itsultra-faint experimental signature. At last, the first observation of CEνNS was recently made by the COHERENT Collaboration using the world's smallest neutrino detector: a 14 kg CsI scintillating crystal. The measurement made use of the pulsed, stopped-pion neutrinos emitted by the Spallation Neutron Source in Oak Ridge, TN. The result confirms the Standard Model prediction and places new constraints on non-standard interactions of neutrinos with nuclei. The collaboration is now deploying additional nuclear targets employing different technologies to further explore this interaction. I will discuss this experimental effort and the first evidence for the CEνNS signal. I will also give an update on the status and prospects for the additional deployments, and summarize the potential scientific impact of this measurement program.

Bounds on new physics from electric dipole moments Dr. Martin Jung - Technical University of Munich, Germany Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Electric dipole moments are extremely sensitive probes for additional sources of CP violation in new physics models. The multi-scale problem of relating the high precision measurements with neutrons, atoms and molecules to fundamental parameters can be approached model-independently to a large extent; however, care must be taken to include the uncertainties from especially nuclear and QCD calculations properly. The resulting bounds on fundamental parameters are illustrated in the context of Two-Higgs-Doublet models.

Search for the electric dipole moment of the neutron Dr. Guillaume Pignol Presentation at 3:45 PM, NPL 178 Coffee and cookies starting at 3:30 PM

Why is there so little antimatter in the Universe? How the matter/antimatter asymmetry
was generated? New physics, beyond the Standard Model, was certainly at play in a
hypothetical phase of the early Universe called baryogenesis. Since this new physics
must induce a violation of CP symmetry, it could be revealed in the laboratory by
measuring a nonzero electric dipole moment of a spin 1/2 particle such as the neutron.
A collaboration of 15 institutions is searching for the neutron electric dipole moment
(nEDM) using the ultracold neutron source at the Paul Scherrer Institute (PSI) in
Switzerland. The most precise measurement of the nEDM has been produced by the
Sussex/RAL/ILL spectrometer at the ILL research reactor in Grenoble, it is compatible
with zero, with the upper limit ?" < 3×10()* ? cm @ 90% C. L. [J.M. Pendlebury et al. PRD
92, 092003 (2015)]. We have operated an upgraded version of this apparatus to take data
at PSI in the period 2015-2017 and we are now building the next generation spectrometer,
In my talk I will present the current status of the measurement and discuss the statistical
and systematical uncertainties. Also, I will present a search for an oscillating nEDM in our
data. Such an oscillation could be induced in a scenario where Dark Matter is formed by
an oscillating Axion-like field.

The neutron lifetime: a haiku Daniel Salvat, Ph.D. CENPA Conference Room NPL-178

Precise knowledge of the free neutron lifetime is required for the prediction of
primordial light element abundances, and is a probe of the charged-current weak
interaction at low energies. The lifetime is primarily measured by either counting
the decay products in a neutron beam of absolutely-known flux, or by trapping
ultracold neutrons (UCN) in material bottles and counting the survivors after
varying time intervals. There is currently a 3.9 standard deviation discrepancy
between these two methods, and new techniques are needed to address this
discrepancy and resolve the neutron lifetime with high precision. The UCNtau
experiment at the Los Alamos Neutron Science Center (LANSCE) consists of a
magnetic UCN trap to eliminate systematic effects related to the absorption and
scattering of neutrons from the walls of previously-used material traps. In addition,
we have developed a novel UCN detector to count the UCN in situ, providing a
powerful check of potential systematic effects. Using the UCNtau apparatus, we
have measured the neutron lifetime to be 877.7 ± 0.7 (stat) +0.3/-0.1 (sys)
seconds, with systematic corrections smaller than their associated uncertainties.
In this talk, I will provide the motivation and context for the measurement, describe
the novel characteristics of the UCNtau experiment, present the results of the
blinded analysis, and discuss potential improvements to the apparatus.

Developing Cyclotron Radiation Emission Spectroscopy, a novel technique for nuclear physics Ben LaRoque (University of California at Santa Barbara) CENPA Conference Room NPL-178

Cyclotron Radiation Emission Spectroscopy is a new approach to measuring electron energies being actively developed by the Project 8 collaboration. The technique determines the energy of individual electrons by observing the changes in their cyclotron frequency resulting from their relativistic mass shifts. Our first demonstration of the methodology was made in 2014 and we have been working since then to evaluate and enhance the performance. Here I will review the principles of CRES and the experimental milestones achieved thus far. I will also briefly discuss progress towards using CRES for nuclear physics applications and specifically direct neutrino mass measurement in Project 8.

Development of low background detectors for high sensitivity measurements. Elena Sala CENPA Conference Room NPL-178

In the field of rare physics events experiments the background reduction plays an important role to distinguish the feeble signal under study above the background. Low level counting techniques are continuously under development to improve the measurement sensitivity. In my presentation I will summarise my contribution in the development and optimisation of both detectors and methods for high sensitivity measurements. I will focus on three main projects I have finalised during my career up to now using germanium detectors. The projects have different purposes spacing from material screening and selection for rare events experiments, to the investigation on natural and artificial radioactivity until the rare decay searches. They are a gamma-gamma coincidence spectrometer, the optimisation of a BEGe detector and the development of a HPGe Array. I will then present the duties and the achievements I reached during my current researcher position.

Measuring g-2 of the electron and positron to test the Standard Model’s most precise prediction. Elise Novitski (Harvard University) CENPA Conference Room NPL-178
Identification of Single Barium Atoms for the nEXO Neutrinoless Double Beta Decay Experiment Scott W. Kravitz (Stanford University) CENPA Conference Room NPL-178

nEXO is a next-generation experiment designed to search for neutrinoless double beta decay of xenon-136 in a liquid xenon time projection chamber. Positive observation of this decay would determine the neutrino to be a Majorana particle, as well as measure the absolute neutrino mass scale. In order to greatly reduce background contributions to this search, the collaboration is developing several "barium tagging'' techniques to recover and identify the decay daughter, barium-136. Barium tagging may be available for a second phase of nEXO operation, allowing for neutrino mass sensitivity beyond the inverted mass hierarchy. Tagging methods for this phase include barium-ion capture on a probe with identification by resonance ionization laser spectroscopy (RIS). An apparatus has been built to deposit barium atoms onto a surface and recover them using infrared laser desorption followed by RIS, with the resulting ions passing through a time-of-flight mass spectrometer for further identification. Recent results from this system will be presented, including those from incorporating an argon ion gun which allows for improved cleaning and preparation of the barium deposition substrate.

Electric Dipole Moment Measurements at Storage Rings Jörg Pretz, RWTH Aachen University & Forschungszentrum Jülich CENPA Conference Room NPL-178

The Electric Dipole Moment (EDM) of elementary particles, including hadrons, is considered as one of the most powerful tools to study the combined violation of charge conjugation (C) and parity (P) symmetry beyond the Standard Model. Such CP violating mechanisms are required to explain the dominance of matter over anti-matter in our universe.

Up to now experiments concentrated on neutral systems, namely neutron, atoms and molecules. Storage rings offer the possibility to measure EDMs of charged particles by observing the influence of the EDM on the spin motion. The Cooler Synchrotron COSY at the Forschungszentrum Jülich provides polarized protons and deuterons up to a momentum of 3.7 GeV/c making it an ideal starting point for such an experimental programme. Plans for measurements of charged hadron EDMs and results of first test measurements will be presented.

Preparing for Advanced LIGO's second observation run and beyond Jenne Driggers from the LIGO Hanford Observatory CENPA Conference Room NPL-178

<p>Advanced LIGO made the first direct detection of gravitational waves during its first observation period, which ended in January 2016. Since then, the interferometers have been undergoing a series of upgrades to improve their sensitivity to various potential gravitational wave sources. I will describe several of these improvements, and how they will enhance our sensitivity to events such as massive black holes at lower frequencies and mergers involving neutron stars at higher frequencies, as well as facilitate tests of general relativity with higher signal-to-noise ratio detections. I will conclude with an outlook on future upgrades that may be added after the next observing run, to further improve our ability to detect gravitational waves.</p>

Search for low-mass dark matter with the CRESST experiment Michael Willers, Technical University of Munich CENPA Conference Room NPL-178

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) experiment, located in the Gran Sasso underground laboratory (LNGS, Italy) aims at the direct detection of dark matter (DM) particles. Scintillating CaWO4 crystals operated as cryogenic detectors are used as target material for DM-nucleus scattering. The simultaneous measurement of the phonon signal from the CaWO4 crystal and the emitted scintillation light in a separate cryogenic light detector is used to discriminate backgrounds from a possible dark matter signal. Since cryogenic detectors are very sensitive to small energy deposits induced, e.g., by the interactions of light DM particles, the experiment is able probe the low-mass region of the parameter space for spin-independent DM-nucleus scattering with high sensitivity.

Recent results from the CRESST-II experiment — obtained using a 300 g detector with a nuclear recoil energy threshold of 307 eV — provide the world best limit for masses below 1.7 GeV/c^2. The CRESST-III experiment aims to significantly improve the sensitivity for low-mass DM particles by using dedicated detector modules. Each such module consists of a ~24 g CaWO4 target crystal and a 20x20 mm^2 Silicon-on-Sapphire light detector and will allow us to reach a nuclear recoil energy threshold of ~100 eV.

Phase 1 of the CRESST-III experiment, where 10 detector modules with a total target mass of 240 g will be operated, recently started its commissioning phase and data taking is expected to start in the summer of 2016. In this talk I will present the most recent results from the CRESST-II experiment as well as the status and future perspectives of the CRESST-III experiment.

Ultra Light Dark Matter and How to Detect It William Terrano, Technical University of Munich CENPA Conference Room NPL-178

<p>Recent theoretical advances show that the parameter space of well-motivated dark matter candidates is much larger than previously thought. I will discuss the nature of these very light dark matter fields and the physical effects it would produce. These effects suggest new techniques are needed to detect this class of dark matter. Promising technologies range from torsion balances to atomic-clocks, co-magnetometers and resonant-cavities.</p>