Sun, YP (reprint author), CAS, Inst High Energy Phys, Beijing 100049, Peoples R China.
BEPCII, the upgrading project of the Beijing Electron-Positron Collider (BEPC), has been designed with a luminosity Of 10(33) cm(-2).s(-1) at the tau-charm energy region. According to the beam-beam simulation results, the luminosity of BEPC 11 with a crossing collision angle of 11 mrad is about 0.50 x 10(33) cm(-2).s(-1) with the original operation mode at the working point of 6.53/5.58. To increase the operating luminosity of the BEPCII, a low momentum compaction factor (alpha(P)) collision mode has been studied which can increase the luminosity to 0.54 x 10(33) cm(-2).s(-1). If the bunch length of the low a, mode is reduced from 1.5 cm to 1.2 cm, a mode with vertical beta function at IP equal to 1.2 cm could push the luminosity to 0.828 x 10(33) cm(-2).s(-1) at the working points 6.53/5.56.