Low-mass vector-meson production at forward rapidity in p+p and Au + Au collisions at √sNN = 200 GeV

Abstract

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low-mass vector-meson (𝜔+𝜌 and 𝜙) production through the dimuon decay channel at forward rapidity (1.2<|y|<2.2) in 𝑝+𝑝 and Au+Au collisions at √𝑠𝑁⁢𝑁=200 GeV. The low-mass vector-meson yield and nuclear-modification factor were measured as a function of the average number of participating nucleons, ⟨𝑁part⟩, and the transverse momentum 𝑝𝑇. These results were compared with those obtained via the kaon decay channel in a similar 𝑝𝑇 range at midrapidity. The nuclear-modification factors in both rapidity regions are consistent within the uncertainties. A comparison of the 𝜔+𝜌 and 𝐽/𝜓 mesons reveals that the light and heavy flavors are consistently suppressed across both 𝑝𝑇 and ⟨𝑁part⟩. In contrast, the 𝜙 meson displays a nuclear-modification factor consistent with unity, suggesting strangeness enhancement in the medium formed.