Neutral meson production in d+Au and p+p collisions at sqrt(s_NN) = 200 GeV in STAR

TL;DR

This paper reports on measurements of neutral meson production at high transverse momentum in p+p and d+Au collisions at 200 GeV, providing insights into medium effects in heavy-ion collisions at RHIC.

Contribution

It presents new high transverse momentum measurements of neutral pions and eta mesons using the STAR detector, enhancing understanding of medium modifications in heavy-ion collisions.

Findings

Results consistent with previous STAR charged hadron data

Agreement with QCD calculations and PHENIX measurements

Observation of medium-induced spectrum modification in d+Au collisions

Abstract

The high centre-of-mass energy of 200 GeV available at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven opens up the hard scattering regime in heavy-ion collisions. Particles at large transverse momentum originate from the early stage of the interaction and, therefore, probe the medium produced in these collisions. To quantitatively understand the medium induced modification of hadron production, precise measurements of identified hadrons in p+p and d+Au systems are required. This thesis presents the high transverse momentum measurements of neutral pions and eta mesons through their di-photon decay channel, performed with STAR Barrel Electromagnetic Calorimeter. The medium induced spectrum modification in d+Au collisions is also measured in comparison to the most peripheral d+Au and to the p+p collisions. The results are consistent with the previous STAR charged hadron measurements and with the theory (QCD) calculations, as well as with measurements from PHENIX, another RHIC experiment.