Dielectron production in 200 GeV p+p and Au+Au collisions at STAR

TL;DR

This paper reports on dielectron production measurements in 200 GeV p+p and Au+Au collisions at STAR, providing insights into in-medium vector meson properties and QGP temperature through dielectron spectra analysis.

Contribution

It presents the first detailed measurement of dielectron mass spectra's centrality and pT dependence in these collisions, comparing results with theoretical models.

Findings

Dielectron spectra vary with collision centrality and pT.

Data show consistency with in-medium vector meson modifications.

Results suggest a connection between dielectron spectra and QGP properties.

Abstract

Leptons do not interact strongly with the hot dense medium created in relativistic heavy ion collisions. They can escape the interaction region undistorted and thus carry direct information about the space-time evolution of the expanding system. In the low mass region (LMR, $0.3<M_{ee}<1.1$ GeV/$c^{2}$), dielectron mass spectra can provide the in-medium vector meson properties, while in the intermediate mass region (IMR, $1.1<M_{ee}<3$ GeV/$c^{2}$), the slope of dielectron transverse mass spectra is expected to have connection with the QGP temperature. In this paper, we present the centrality and $p_{T}$ dependence of the dielectron mass spectra measured in STAR experiment at RHIC. The data sets used in the analysis include large statistics samples collected during years 2010 for 200 GeV Au+Au collisions and 2012 for 200 GeV p+p collisions. In order to extract underlying physics, we will compare our results with model calculations.