1) Update on run13 MTD J/psi cross-section - Te-Chuan Huang
Te-Chuan found two strange peak in the TPC Vz - VPD Vz distributions, one at about -300 cm and the other one at about 40 cm.

• the bump at -300 cm is due to VPD Vz overflow (Short_t). 25ns shift in the TOF TDC could be the reason for large VPD Vz
• the bump at 40 cm could be due to statistical fluctuation. Te-Chuan studied with MC. It is also suggested to directly calculate the probability based on the distributions shown on slide  14 as a cross-check.