Simulation study of particle identification using cluster counting technique for the BESIII drift chamber

The particle identification of charged hadrons, especially for the separation of K and pi, is crucial for the flavour physics study. Ionization measurement with the cluster counting technique, which has a much less fluctuation than traditional dE/dx measurement, is expected to provide better particle identification for the BESIII experiment. Simulation studies, including a Garfield++ based waveform analysis and a performance study of K/pi identification in the BESIII offline software system have been performed. The results show that K/pi separation power and PID efficiency would be improved appreciably in the momentum range above 1.2 GeV/c using cluster counting technique even with a conservative resolution assumption.