Studies of dE/dx measurements with the BESⅢ

The Beijing Spectrometer HI (BESIII) is a general-purpose detector used for the study of tau-charm physics at the Beijing Electron-Positron Collider II (BEPC II). This paper presents our studies of the dE/dx measurement in the drift chamber of BESIII, which is important for the identification of charged particles. Corrections applied to the dE/dx measurement in data reconstruction are discussed. After our current dE/clx calibration, a resolution of about 6% has been obtained for minimum ionization particles, and a 3 sigma K/pi separation is obtained for momenta up to 760 MeV/c. These results meet the design goals of the BESIII drift chamber.