Low-mass vector-meson production at forward rapidity in $p$$+$$p$ and Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$~GeV

TL;DR

This study measures low-mass vector-meson production at forward rapidity in proton-proton and gold-gold collisions at 200 GeV, revealing suppression patterns and strangeness enhancement in the quark-gluon plasma.

Contribution

First measurement of low-mass vector-mesons at forward rapidity in $p+p$ and Au+Au collisions at 200 GeV, comparing decay channels and nuclear modification factors.

Findings

Light and heavy flavor mesons are suppressed similarly across $p_T$ and participant number.

The $ ext{phi}$ meson shows no suppression, indicating strangeness enhancement.

Results are consistent with previous midrapidity measurements.

Abstract

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low-mass vector-meson ($\omega+\rho$ and $\phi$) production through the dimuon decay channel at forward rapidity $(1.2<|\mbox{y}|<2.2)$ in $p$$+$$p$ and Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$~GeV. The low-mass vector-meson yield and nuclear-modification factor were measured as a function of the average number of participating nucleons, $\langle N_{\rm part}\rangle$, and the transverse momentum $p_T$. These results were compared with those obtained via the kaon decay channel in a similar $p_T$ range at midrapidity. The nuclear-modification factors in both rapidity regions are consistent within the uncertainties. A comparison of the $\omega+\rho$ and $J/\psi$ mesons reveals that the light and heavy flavors are consistently suppressed across both $p_T$ and ${\langle}N_{\rm part}\rangle$. In contrast, the $\phi$ meson displays a nuclear-modification factor consistent with unity, suggesting strangeness enhancement in the medium formed.