Two particle correlations with photon and pi0 triggers in ALICE at LHC

TL;DR

This paper analyzes two-particle correlations involving photons and pi0 mesons in proton-proton collisions at the LHC to understand medium modifications in heavy-ion collisions, using azimuthal correlations to extract partonic momentum.

Contribution

It introduces a method to measure partonic momentum and medium effects through photon and pi0 triggered correlations in proton-proton collisions as a baseline for heavy-ion studies.

Findings

Observation of di-jet correlation patterns

Extraction of partonic transverse momentum $k_{T}$

Baseline data for heavy-ion collision comparisons

Abstract

Comparing the measurements of the hadronic final state from partonic showers in proton-proton and heavy-ion collisions will reveal the modifications generated by the medium on partons produced in hard scatterings. This can be achieved by selecting the hard processes in which there is a direct photon in the final state. The experimental technique consists in tagging events with a well identified high energy direct photon and in measuring the azimuthal angle correlation with charged hadrons. To establish a reference measurement for heavy-ion collisions, proton-proton collision data collected with ALICE have been analyzed. Preliminary results are presented together with photon and $\pi^{0}$-charged hadrons correlations showing the characteristic di-jet pattern from where the partonic momentum $k_{T}$ is extracted.