Predicting parton energy loss in small collision systems

TL;DR

This paper predicts the potential for observing parton energy loss in small collision systems at the LHC, analyzing model assumptions against existing data and providing forecasts for oxygen-oxygen collisions.

Contribution

It offers the first comprehensive predictions for parton energy loss signals in small systems like oxygen-oxygen at the LHC, testing various models against existing heavy-ion data.

Findings

Model assumptions tested against lead-lead and xenon-xenon data.

Predictions made for charged hadron nuclear modification factor in oxygen-oxygen collisions.

Evidence suggests possible parton energy loss in small systems.

Abstract

Medium induced parton energy loss is not conclusively established neither in very peripheral heavy-ion collisions nor in proton-ion collisions. However, the standard interpretation of azimuthal momentum anisotropies in theses systems implies some partonic rescattering. The upcoming light-ion runs at the LHC provide a unique opportunity to search for parton energy loss in different systems of similar size. Here, we make predictions for the expected parton energy loss signal in the charged hadron spectra in a system size scan at LHC. We test a large set of model assumptions against the transverse momentum and centrality dependence of the charged hadron nuclear modification factor in lead-lead and xenon-xenon collisions at the LHC. We then attempt to make a model agnostic prediction for the charged hadron nuclear modification factor in oxygen-oxygen collisions.