Probing Nuclear Matter with Jet Conversions

TL;DR

This paper explores how the flavor composition of high-energy jets can serve as a probe of the quark-gluon plasma in nuclear collisions, highlighting the potential of flavor measurements to complement traditional energy loss studies.

Contribution

It introduces the concept of jet flavor conversions as a new method to study jet-medium interactions and provides estimates for their rates within a Fokker-Planck framework.

Findings

Jet flavor ratios can significantly differ in nuclear matter compared to proton-proton collisions.

Jet conversions can be quantitatively estimated and impact high-$p_T$ hadron measurements.

Flavor observables offer a novel way to probe the properties of the quark-gluon plasma.

Abstract

We discuss the flavor of leading jet partons as a valuable probe of nuclear matter. We point out that the coupling of jets to nuclear matter naturally leads to an alteration of jet chemistry even at high transverse momentum $p_T$. In particular, QCD jets coupling to a chemically equilibrated quark gluon plasma in nuclear collisions, will lead to hadron ratios at high transverse momentum $p_T$ that can differ significantly from their counterparts in $p+p$ collisions. Flavor measurements could complement energy loss as a way to study interactions of hard QCD jets with nuclear matter. Roughly speaking they probe the inverse mean free path $1/\lambda$, while energy loss probes the average squared momentum transfer $\mu^2/\lambda$. We present some estimates for the rate of jet conversions in a consistent Fokker-Planck framework and their impact on future high-$p_T$ identified hadron measurements at RHIC and LHC. We also suggest some novel observables to test flavor effects.