Probing nuclear modifications of parton distribution functions through the isolated prompt photon production at the LHC

TL;DR

This paper investigates how isolated prompt photon production in p-Pb collisions at the LHC can reveal nuclear modifications of parton distribution functions, especially antishadowing effects, by analyzing different energies and rapidities.

Contribution

It provides a comprehensive analysis of prompt photon production to identify optimal kinematic regions sensitive to nuclear parton modifications, focusing on antishadowing effects.

Findings

Identifies backward rapidity regions most sensitive to nuclear modifications.

Shows energy and rapidity dependence of prompt photon production.

Highlights the importance of specific kinematic conditions for experimental measurements.

Abstract

An accurate knowledge of nuclear parton distribution functions (nPDFs) is an essential ingredient of high energy physics calculations when the processes are involving nuclei in the initial state. It is well known now that the prompt photon production both in hadronic and nuclear collisions is a powerful tool for exploring the parton densities in the nucleon and nuclei especially of the gluon. In this work, we are going to perform a comprehensive study of the isolated prompt photon production in $ p $-Pb collisions at backward rapidities to find the best kinematic regions in which the experimental measurements have most sensitivity to the nuclear modifications of parton densities. Most emphasis will be placed on the antishadowing nuclear modification. To this aim, we calculate and compare various quantities at different values of center-of-mass energy covered by the LHC and also different rapidity regions to realize which one is most useful.