J/{\psi} and {\Upsilon} measurements via the di-muon channel in Au + Au collisions at $\sqrt{s_{\rm{NN}}}$ = 200 GeV with the STAR experiment

TL;DR

This paper reports on the first measurements of J/ψ suppression and elliptic flow, as well as Upsilon state separation, via the di-muon channel in Au+Au collisions at 200 GeV using the STAR experiment's new Muon Telescope Detector.

Contribution

It introduces the first use of the Muon Telescope Detector at STAR for quarkonium measurements via the di-muon channel, enabling new insights into quarkonium suppression and state separation.

Findings

J/ψ suppression decreases with increasing transverse momentum.

Elliptic flow of J/ψ is consistent with zero above 2 GeV/c.

Initial measurements of Upsilon states are presented within current statistical limits.

Abstract

Measurements of quarkonium production in heavy-ion collisions have played an essential role in understanding the properties of the Quark Gluon Plasma created in such collisions. In early 2014, the Muon Telescope Detector, designed to trigger on and identify muons based on its precise timing information, was fully installed in STAR. It opens the door to measure quarkonia via the di-muon channel for the first time at the STAR experiment, with the potential to separate different {\Upsilon} states. In this talk, we present the measurements of J/{\psi} suppression and elliptic flow at mid-rapidity in Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 200 GeV down to low transverse momentum ($p_{\rm{T}}$). The suppression is found to decrease with increasing $p_{\rm{T}}$ while the elliptic flow is consistent with 0 for $p_{\rm{T}}$ above 2 GeV/c. Furthermore, the measurement of different {\Upsilon} states is explored within the precision of the available statistics.