Measurement of ω mesons via radiative decay mode in √s=200 GeV Au+Au collisions at RHIC-PHENIX

We report on omega mesons' production via radiative decay mode (omega -> pi(0)gamma,pi(0) -> 2 gamma) in root s = 200 GeV Au+Au collisions at RHIC-PHENIX. The main difficulty of this analysis is the huge combinatorial background inevitable for reconstructing particles from the three-body decay mode. The emphasis is on the feasibility study using both simulation and real data to search the best parameters that improve S/root B. For this purpose, we examine several sets of energy and momentum cuts for selecting pi(0) and K-s(0). To evaluate the remaining background, we consider three background sources; correlated/uncorrelated background and K-s(0) contribution, then we subtract them. The amount of these contributions is determined by a fit on a mass spectrum. The result suggests that omega meson production is suppressed in central Au+Au collisions at high pT region.