The results of a study of event tagging strategies for elementary physics processes in theτ-charm region are presented.The algorithm for online event filtering is optimized by adopting the information provided by different sub-detectors according to their strengths and capacities.The algorithm is tested with various generated physics and background events.The results indicate that the algorithm satisfies the requirements of BESⅢphysics analysis and its DAQ system.
The calibration algorithm for RPC-based muon detector at BESⅢ has been developed. The calibration method, calibration error and algorithm performance are studied. The primary results of efficiency and noise at layer, module and strip levels have been calibrated with cosmic ray data. The calibration constants are available for simulation and reconstruction tuning. The results of Monte Carlo and data are also compared to check the validation and reliability of the algorithm.
The absolute energy calibration with photons from π0's for the BESⅢ EMC is discussed. Using 3 million hadronic events, the preliminary results are presented. Precision of about 1% in the photon energy measurement is obtained from crossing check using photons in ψ(2S)→γχc1,2(1P).
Software alignment is quite important for a tracking detector to reach its ultimate position accuracy and momentum resolution. We developed a new alignment algorithm for the BESⅢ Main Drift Chamber using the Kalman Filter method. Two different types of data which are helix tracks and straight tracks are used to test this algorithm, and the results show that the design and implementation is successful.
