BESIII Time-of-Flight Beam Test Simulation And Offline Software Development

The upgrade project of the Beijing Electron Positron Collider known as BEPC II is carried through now. The luminosity of BEPCII will be increased by two orders, and the performance of its detector BESIII, upgraded version of Beijing Electron Spectrometer (BES), will be improved significantly. Time of Flight (TOF) counters as one of its sub-detector is mainly used to measure the time of flight of charged particles for particle identification. This thesis is focused on the beam test of BESIII TOF detector and the Monte Carlo simulation, as well as the design of TOF offline reconstruction and calibration software.BESIII TOF prototype beam test is done with an 800MeV electron beam provided by the BEPC-Linac. The performance of BESIII TOF is well studied. The results indicate that the BESIII TOF can reach its expected design goal. The test results for scintillators of different thickness show that the one of 5cm thickness has the best time resolution. When the scintillator is wrapped with different reflectivity material, the time resolution using aluminum film is better than ESR film, although the reflectivity of ESR film is higher than that of aluminum film. Based on Geant4 the Monte Carlo simulation study on BESIII TOF prototype beam test is done. The simulation results are consistent with what obtained from beam test, and therefore make us further understand that the results from beam test could be well explained by the outputted PMT pulse amplitude and its raise time in different cases.Under the framework of BESIII offline data analysis, The BESIII TOF offline reconstruction and calibration system has been developed based on Objected-Oriented C++ language. The BESIII TOF reconstruction system has been tuned and tested using Monte Carlo data, associated with the main draft chamber reconstruction system and track extrapolation system. Some test results are given. It shows that the BESIII TOF reconstruction system works quite well, the reconstructed results have been used in physics analysis software. The BESIII calibration system has also been tested using Monte Carlo Bhabha events. The calibration constants obtained have been used into the TOF reconstruction system.Based on BOSS5.0.0,preliminary checks have been done for some physics subjects using M.C data,such as the efficiency of hadron reconstruction and PID.and its application...