Nuclear Modification of ${\ensuremath{\psi}}^{\ensuremath{'}}$, ${\ensuremath{\chi}}_{c}$, and $J/\ensuremath{\psi}$ Production in $d+\mathrm{Au}$ Collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$

Nuclear Modification of $ψ^{'}$ , $χ_{c}$ , and $J / ψ$ Production in $d + Au$ Collisions at $\sqrt{s_{N N}} = 200 GeV$

A. Adare et al. (PHENIX Collaboration)

Phys. Rev. Lett. 111, 202301 – Published 12 November 2013

Abstract

We present results for three charmonia states ( $ψ^{'}$ , $χ_{c}$ , and $J / ψ$ ) in $d + Au$ collisions at $| y | < 0.35$ and $\sqrt{s_{N N}} = 200 GeV$ . We find that the modification of the $ψ^{'}$ yield relative to that of the $J / ψ$ scales approximately with charged particle multiplicity at midrapidity across $p + A$ , $d + Au$ , and $A + A$ results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the $ψ^{'}$ and $J / ψ$ , while in small-impact-parameter collisions the more weakly bound $ψ^{'}$ is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger $ψ^{'}$ suppression in central events is not explained by an increase of the nuclear absorption owing to meson formation time effects.