Minimizing Selection Bias in Inclusive Jets in Heavy-Ion Collisions with Energy Correlators

TL;DR

This paper introduces a new ratio of energy correlator observables that significantly reduces selection bias in heavy-ion jet measurements, enabling clearer insights into medium modifications and parton-hadron dynamics.

Contribution

A novel ratio of energy correlator observables is proposed to mitigate selection bias effects in heavy-ion collision jet analyses.

Findings

Selection bias impact reduced by an order of magnitude in simulations

The new ratio retains sensitivity to medium modifications

Method can be directly applied to experimental CMS data

Abstract

The first-ever measurement of energy correlators within inclusive jets produced in heavy-ion collisions, revealed by the CMS Collaboration, shows a clear enhancement at large angles relative to the proton-proton (p-p) baseline. However, interpreting this enhancement is complicated due to selection bias from energy loss, which also distorts the energy correlator heavy-ion to p-p ratio in the hadronization region, hindering our understanding of parton/hadron dynamics in a colored medium. In this Letter, we introduce a new ratio of energy correlator observables that removes the leading effects of selection bias from the two-point energy correlator spectrum (E2C). Pythia and Herwig simulations show that the impact of selection bias in the E2C is reduced by an order of magnitude, while sensitivity to any other medium modifications is retained. This quantity can be obtained directly from the experimental measurements presented by CMS, as illustrated in the accompanying note.