UH BES Group

High Energy Physics Group

Watanabe Hall, 2505 Correa Road, Honolulu, Hawaii

Phone: (808)956-7391

FAX: (808) 956-2930

    The University of Hawaii High Energy Physics Group is part of the Beijing Electron Spectrometer (BES) experiment, which is an international collaboration involving many US and Chinese universities and laboratories. The BES detector, located at the Bejing Electron Positron Collider (BEPC) at the Institute of High Energy Physics (IHEP) in Beijing, records information from electron positron interactions in the tau-charm energy region from 3 - 5 GeV. This region provides rich and unique opportunities for studies of Tau leptons, D mesons, J/psi, and psi prime events.
     BEPCII is a high luminosity, multi-bunch collider, which requires a comparable high quality detector with the modern detector technology. On the one hand, the existing BESII detector is facing severe aging problems, and its electronics and data acquisition system do not support the multi-bunch mode; on the other hand, a factor of 100 increases of statistics requires a corresponding reduction of systematic errors. Therefore a modern detector, BESIII, has to be built to meet the following requirements: 1. Very good photon energy resolution, good angle resolution for photon measurement. Crystal calorimeter, such as CsI, is one of the best choice. 2. Accurate 4-momenta measurement of low momentum charged particles. A drift chamber based on He gas is one of the best choice. 3. Good hadron identification capabilities. Both Cherenkov detector and Time-of-Flight system can meet our requirements. 4. A modern data acquisition system and the front-end electronics system based on the pipeline technique, which can accommodate multi-bunch mode. The choice of the detector components is based on physics requirements, existing experience in the collaboration, budgetary and schedule constraints, etc., which consists of the following components: 1. A He gas based drift chamber with a single wire resolution better than 130mm; 2. A CsI calorimeter with an energy resolution better than 2.5%@1 GeV; 3. A Time-of-Flight system with a time resolution better than 100 ps; 4. A super-conducting solenoid magnet with a field of 1.0 Tesla; 5. A RPC based muon chamber system.
     More information on the BESIII experiment at the high luminosity tau-charm factory, please see the Yifang Wang's report at Charm 2007 Meeting.