A unified description of small, peripheral, and large system suppression data from pQCD

TL;DR

This paper provides a unified pQCD-based framework to describe suppression data across small, peripheral, and large nuclear collision systems, revealing surprising similarities and model-insensitive results.

Contribution

It introduces a comprehensive model that predicts nuclear modification factors across different collision systems, aligning with some experimental data and challenging existing interpretations.

Findings

Suppression in small and peripheral systems can be described by the same model.

Predictions match PHENIX data but conflict with ATLAS results.

Suppression equivalence is insensitive to the energy loss model used.

Abstract

We present quantitative predictions for the nuclear modification factor in both small and peripheral systems from a pQCD-based energy loss model that is constrained by light- and heavy-flavor suppression data from central heavy-ion collisions. We find nearly identical suppression for central $p / d + A$ collisions as for peripheral $A + A$ collisions, quantitatively consistent with the measured 20% suppression of neutral pions produced in $d + \mathrm{Au}$ collisions by PHENIX, but dramatically inconsistent with the measured 20% enhancement of charged hadrons produced in $p + \mathrm{Pb}$ collisions by ATLAS. We demonstrate that this equivalence of central small system suppression and peripheral large system suppression is insensitive to the underlying energy loss model.