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

Abstract

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low-mass vector-meson ($\ddot{I}‰+\ddot{I}$ and $\ddot{I}•$) 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, $⟨N_{\mathrm{part}}⟩$, 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 $\ddot{I}‰+\ddot{I}$ and $J/\ddot{I}ˆ$ mesons reveals that the light and heavy flavors are consistently suppressed across both $p_T$ and $⟨N_{\mathrm{part}}⟩$. In contrast, the $\ddot{I}•$ meson displays a nuclear-modification factor consistent with unity, suggesting strangeness enhancement in the medium formed.

356 authors from 71 institutions, 14 pages, 14 figures, 1 table. v1 is version submitted to Physical Review C. HEPdata tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.html