Upsilon measurement in STAR

TL;DR

This paper reports preliminary measurements of Upsilon particle production in proton-proton collisions at 200 GeV, using the STAR detector, with results consistent with pQCD predictions.

Contribution

First measurement of Upsilon production at STAR in p+p collisions at 200 GeV, including experimental setup and analysis methods.

Findings

Production cross-section matches pQCD expectations

Developed specialized trigger for electron detection

Analyzed Upsilon decay to electron-positron pairs

Abstract

We present preliminary results of Upsilon production in p+p collisions at sqrt(s)=200 GeV at central rapidity. This measurement was performed at the STAR experiment through the Upsilon->e^+e^- decay channel. In this manuscript we describe the experimental details, from the development of a specially designed trigger setup to the analysis methods used to discriminate electrons from hadrons. The production cross-section obtained B*{(dsigma/dy)|(y=0)}=91(28)(22) pb is compatible with our expectations based on pQCD calculations.