Measurement of Non-photonic Electrons in p + p Collisions at $\sqrt{s_{NN}}$ = 200 GeV with reduced detector material in STAR

TL;DR

This study measures non-photonic electron production in proton-proton collisions at 200 GeV, achieving a tenfold reduction in background electrons due to detector modifications, which enhances the precision of charm quark cross-section measurements.

Contribution

The paper demonstrates a significant reduction in photonic background electrons by removing inner detector material, improving the accuracy of non-photonic electron measurements in STAR.

Findings

Photonic background electrons reduced by a factor of 10.

Enhanced signal-to-background ratio for non-photonic electrons.

Improved potential for precise charm cross-section extraction.

Abstract

In this paper, we present our analysis of mid-rapidity non-photonic electron (NPE) production at pT >0.2GeV/c in p+p collisions at $\sqrt{s_{NN}}$ = 200 GeV. The dataset is about 78M TOF-triggered events taken from RHIC year 2008 runs. Through the measurement of e/\pi ratio, we find that the photonic background electrons from gamma conversions are reduced by about a factor of 10 compared with those in STAR previous runs due to the absence of inner tracking detectors and the supporting materials. The dramatic increase of signal-to-background ratio will allow us to improve the precision on extracting the charm cross-section via its semi-leptonic decays to electrons.