IMPROVEMENT OF SIGNAL/NOISE RATIO FOR STUDYING LOW-MASS VECTOR MESONS VIA DI-ELECTRON DECAY CHANNEL IN PHENIX

The yields of low mass vector mesons via e+e− decay channels in Au + Au collisions at have been measured by the RHIC-PHENIX experiment. The measurement provides important information to study chiral symmetry restoration in high temperature medium created in high energy heavy-ion collisions. One of the major difficulties in the measurement is huge backgrounds due to high multiplicity environments. Analysis methods have been improved to reduce the background. The invariant yield of ω mesons is found to scale with the number of participant nucleons. The invariant pT spectrum of ω mesons in minimum bias collisions is in a good agreement with other decay channels and in other collision systems.