Elementary particle physics

The University of Texas at Dallas (UTD) is participating in two e(+)e(-), experiments, Beijing Spectrometer (BES) and BABAR, the PEP-11 B Factory detector. Associated production of tau and charmed mesons allow for absolute branching fraction measurements with good control of backgrounds. BES is uniquely positioned to study the leptonic and hadronic decays of quarkonia. The Beijing Electron Positron Collider (BEPC) delivers luminosities an order of magnitude higher than earlier facilities. BES and BEPC will be upgraded following the 1994-5 run, and will resume data taking in Fall, 1996 with an improved detector and a Three-fold increase in luminosity. The raison d'etre of BABAR is the exploration of CP violation in the B meson system. An asymmetric storage ring is required to observe the time-dependence of the CP asymmetry. Other BABAR physics includes measurements of CKM matrix elements, rare B decays, penguin diagrams, B(sub s) decays, and precision measurements of tau and D meson decays. The scheduled BABAR turn-on in 1999 provides the UTD group with a natural evolution with continuous physics during this period.