ϕ meson measurements and flavor-dependent nuclear suppression at RHIC-PHENIX

Abstract

Measurement of low mass vector mesons (ρ, ω, ϕ) provides important information to understand the properties of quark–gluon plasma (QGP) created in the central heavy-ion collision at RHIC. The mass and branching ratio of the ϕ meson decay into di-electron and di-kaon could be modified in the excited vacuum due to the effect of partial chiral symmetry restoration. In addition, ϕ meson contains hidden strangeness and hence its measurement can figure out the strangeness production. The suppression pattern of ϕ meson with high transverse momentum in heavy-ion collisions, compared to scaled p + p results, provides the information to understand the mechanism of production and energy loss of strange quark with the strongly coupled matter. The PHENIX experiment at RHIC has measured the ϕ meson production in p+p, d+Au and Au+Au collisions at up to 200 GeV at mid-rapidity. In this paper, we will present recent PHENIX results about the ϕ meson production. The mass peaks for ϕ have been observed in both di-electron and di-kaon invariant mass spectra. The extracted spectra, mass and width of ϕ in p+p, d+Au and Au+Au are reviewed. Moreover, we compare the nuclear modification factors of various hadrons and discuss flavor dependence of their suppression patterns.