$\Upsilon$ production in p+p and Au+Au collisions in STAR

TL;DR

This paper reports on measurements of $$ production in proton-proton and gold-gold collisions at 200 GeV, providing insights into quarkonium suppression and the properties of the quark-gluon plasma.

Contribution

First measurements of $$ production in Au+Au collisions at RHIC, expanding understanding of quarkonium behavior in hot nuclear matter.

Findings

Observation of $$ signals in p+p collisions.

First $$ results in Au+Au collisions at RHIC.

Implications for quark-gluon plasma properties.

Abstract

The study of quarkonium production in relativistic heavy ion collisions provides insight into the properties of the produced medium. The lattice studies show a sequential suppression of quarkonia states when compared to normal nuclear matter; which further affirms that a full spectroscopy including bottomonium can provide us a better thermometer for the matter produced under extreme conditions in relativistic heavy ion collisions. With the completion of the STAR Electromagnetic Calorimeter and with the increased luminosity provided by RHIC in Run 6 and 7, the study of $\Upsilon$ production via the di-electron channel becomes possible. We present the results on $\Upsilon$ measurements in p+p collisions (from Run 6) along with the first results from Au+Au collisions (in Run 7) at $\sqrt{s_{\rm{NN}}} = 200$ GeV from the STAR experiment.