Seminars and Colloquia

Title Speaker Location Material
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
detector.

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,
n2EDM.
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>