ϕ meson production in Au+Au and p+p collisions at sNN=200GeV

Abstract We report the STAR measurement of ϕ meson production in Au + Au and p + p collisions at s N N = 200 GeV . Using the event mixing technique, the ϕ spectra and yields are obtained at mid-rapidity for five centrality bins in Au + Au collisions and for non-singly-diffractive p + p collisions. It is found that the ϕ transverse momentum distributions from Au + Au collisions are better fitted with a single-exponential while the p + p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that ϕ production in central Au + Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions ( 〈 N bin 〉 ) . The systematics of 〈 p t 〉 versus centrality and the constant ϕ / K − ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for ϕ production.