Selection bias effects on high-$p_\mathrm{T}$ yield and correlation measurements in Oxygen+Oxygen collisions

TL;DR

This paper investigates how selection bias affects high-$p_\mathrm{T}$ measurements in Oxygen+Oxygen collisions, highlighting differences between RHIC and LHC, and comparing bias effects across different centrality definitions and simulation models.

Contribution

It provides a systematic survey of centrality bias effects on high-$p_\mathrm{T}$ yields and correlations in O+O collisions using Monte Carlo generators, informing experimental analysis.

Findings

Bias factors show non-trivial $p_\mathrm{T}$ dependence at RHIC.

Multiplicity-based centrality is less sensitive to bias than energy-based.

Correlation measurements are less affected by bias than yield measurements.

Abstract

Oxygen+Oxygen (O+O) collisions at RHIC and the LHC offer a unique experimental opportunity to observe the onset of jet quenching in intermediate relativistic collision systems. As with the smaller proton-nucleus or larger nucleus-nucleus systems, measurements of centrality-selected high-$p_\mathrm{T}$ processes in O+O collisions are expected to be sensitive to selection bias effects, which will be necessary to quantify or mitigate before a definitive conclusion on the presence of jet quenching. Using two Monte Carlo heavy-ion event generators, we provide a survey of centrality bias effects on high-$p_\mathrm{T}$ yield and correlation measurements. Some highlights of our findings include that (1) bias factors for the accessible kinematic range at RHIC show a non-trivial $p_\mathrm{T}$ dependence, compared to a negligible one at the LHC given the smaller accessible Bjorken-$x$ range, (2) centrality definitions based on multiplicity are less sensitive to bias effects than those based on the transverse energy, (3) the Angantyr generator gives qualitatively similar but larger-magnitude bias factors than HIJING, and (4) correlation measurements have a much smaller sensitivity to bias effects than do yield measurements. The findings here are intended to guide the experimental design and interpretation of O+O jet quenching and other hard-process measurements.