Last year the Nuclear Physics Laboratory (NPL) officially became the Center for Experimental Nuclear Physics and Astrophysics (CENPA), with an expanded mandate. CENPA includes the activities of the former NPL and in addition fosters collaborative work among the members of the NPL and others in the University of Washington Physics Department and elsewhere. CENPA pursues a broad program of research in nuclear physics, astrophysics and related fields. Research activities are conducted locally and at remote sites. The current program includes "in-house" research on nuclear collisions and fundamental interactions using the local tandem Van de Graaff and superconducting linac accelerators, as well as local and remote non-accelerator research on fundamental interactions and user-mode research on relativistic heavy ions at large accelerator facilities in the U.S. and Europe.

A good ⁷Be(p,g)⁸B Phase I data taking run has been completed and the data are being analyzed. We used a 100 mCi target fabricated on a newly designed post backing with a breakaway washer, eliminating unwanted target tails. All important sources of systematic error were measured, including loss of ⁸B due to backscattering out of the target. We expect to meet our goal of 5% precision on the cross section and the astrophysical S-factor.

The SNO detector has been running in a production mode with pure heavy water in the acrylic vessel since November 1999. Analysis of the data taken since that time has been directed towards a measurement of the rate of charged-current interactions of ⁸B neutrinos, and will be completed soon. Both the SNO collaboration and the scientific community await this milestone with interest.

A new collaboration of CENPA members with the University of Mainz, Kernforschungszentrum Karlsruhe, and other institutions to carry out a large-scale experiment on tritium beta decay has formed. The objective is a direct kinematic measurement of the mass of the electron antineutrino with 0.5-eV sensitivity.

The notion of "large extra dimensions" has recently attracted a great deal of attention, particularly as a solution of the gravitational hierarchy problem. For example, the "true" Planck mass could be lowered to about 1 TeV if two of the extra 7 dimensions of string theory had sizes of around 1 mm. This would show up as a violation of the gravitational inverse-square law for separations less than a milimeter. We recently used a novel torsion balance instrument to test the inverse-square law down to 0.2 mm and found no evidence for anomalies, which implies an unification mass of > 3.5 TeV.

The big news in ultrarelativistic heavy ion physics this year is first data from the RHIC collider. Experimental results have been pouring in from all four experiments. The UW event-by-event program has pioneered a number of novel analysis techniques that are now being brought to bear on the first batch of STAR data. We have seen for the first time substantial dynamical fluctuations in event-wise mean transverse momentum, possibly signaling new QCD effects in Au-Au collisions, and charge- or isospin-dependent correlation structures possibly connected to novel structure on the hadronic freezeout surface formed during rapid traversal of the QCD phase boundary.

A study of collision-induced multifragmentation of C₆₀ has been completed. Multifragmentation into three or more fragments each with three or more carbons in each fragment is found to be an important reaction channel for large deposition energies. An odd-even dependence of fragment yields implies sequential decay of chain or ring multifragmentation products.

As always, we encourage outside applications for the use of our facilities. As a convenient reference for potential users, the table on the following page lists the capabilities of our accelerators. For further information, please contact Prof. Derek W. Storm, Executive Director, Nuclear Physics Laboratory, Box 354290, University of Washington, Seattle, WA 98195; (206) 543-4080, or storm@npl.washington.edu. Further information is also available on our web page: http://www.npl.washington.edu .

We close this introduction with a reminder that the articles in this report describe work in progress and are not to be regarded as publications or to be quoted without permission of the authors. In each article the names of the investigators are listed alphabetically, with the primary author, to whom inquires should be addressed, underlined.

Derek Storm, Editor
storm@npl.washington.edu (206) 543-4085

Barbara Fulton, Assistant Editor