University of California, Santa Cruz SCIPP Santa Cruz Institute for Particle Physics

Personal Statement

Over the past ten years, scattering experiments have provided a wealth of new information on the nature of the strong and electroweak forces. An experimental particle physicist, William Lockman is currently working on the BaBar experiment at SLAC, whose major goal is to find and measure CP-violation in the decays of neutral B-mesons produced at the Upsilon(4S) resonance. The crux to studying CP-violations in the B-system is to measure the time interval between the two B-meson decays. The experiment is situated at the world's highest luminosity storage ring facility, PEP-II and additionally benefits from the simple initial state, the boosted center-of-mass and precision vertexing, charged tracking, particle ID and calorimetry of the BaBar detector.

Over the past three years, Lockman has directed the development of the BaBar detector simulation program. The particle-tracking part of the simulation, bbsim, which is based on the Geant3.21 toolkit, is now being replaced by a C++ application layer based on the much more extensive object-oriented Geant4 toolkit. The Geant4-based code is currently being validated and is expected to be used in production mode by January, 2001.

Lockman is coordinating the BaBar physics efforts at SCIPP and working with SCIPP colleagues on searches for (i) D^0 bar D^0-mixing and (ii) CP violation in singly Cabibbo-suppressed D-meson decays A non-zero signal in either case might be an indication of new physics beyond the standard model. Process (ii) also provides an independent check of CP measurements in B decays. These measurements benefit from the high luminosity storage ring and precision vertexing, tracking, particle ID and calorimetry of the BaBar detector.

Collaboration Involvement: BaBar