Isolated photon-hadron correlations in proton-proton collisions at {\sqrt(s)} = 7 TeV with the ALICE experiment

TL;DR

This paper reports on measurements of isolated photon-hadron correlations in proton-proton collisions at 7 TeV using the ALICE experiment, providing insights into jet fragmentation and QCD processes.

Contribution

First measurement of isolated photon-hadron correlations in pp collisions at 7 TeV with the ALICE detector, including statistical subtraction of decay photon contamination.

Findings

Extraction of xE distributions for photon-hadron and π0-hadron correlations.

Method for isolating direct photons and subtracting decay photon background.

Insights into jet fragmentation in high-energy pp collisions.

Abstract

At high pT, direct photons produced in Compton and annihilation QCD leading order processes are associated to a jet in the opposite direction. Such processes are tagged experimentally by identifying leading isolated photons and their correlated associated hadrons in the opposite azimuthal direction. The jet fragmentation can be estimated from the hadrons and the photon via the imbalance parameter xE. We present the results extracted from gamma-hadron correlations measured by the ALICE experiment in pp collisions at {\sqrt(s)} = 7 TeV. Direct photons are first identified using isolated criteria. Then, the remaining contamination from neutral mesons decay photons is subtracted statistically to extract the xE distributions of isolated photon-hadron and isolated {\pi}^0-hadron correlations.