Understanding mass hierarchy in collisional energy loss through heavy flavor data

TL;DR

This paper investigates the mass hierarchy in heavy flavor suppression within quark-gluon plasma, deriving a direct relation between collisional energy loss and quark mass, and proposing an observable for future experimental testing.

Contribution

It introduces a new analytical relation linking collisional energy loss to quark mass and proposes an observable to isolate this effect in high-precision experiments.

Findings

Derived a direct analytical relation between collisional suppression and quark mass.

Proposed a novel observable sensitive solely to collisional energy loss.

Numerically extracted the mass hierarchy in collisional energy losses.

Abstract

While experimental observations, such as the mass hierarchy effect, are attributed and analyzed within radiative models, their interpretation crucially depends on collisional energy loss contribution, which is often neglected in such analyses. To our knowledge, neither a (direct) simple relation between collisional energy loss and heavy quark mass is established, nor an observable that quantifies this effect. On the other hand, the upcoming high-luminosity measurements at RHIC and LHC will generate heavy flavor data with unprecedented precision, providing an opportunity to utilize high-pT heavy flavor data to analyze the interaction mechanisms in the quark-gluon plasma. To this end, we employ a recently developed DREENA framework based on our dynamical energy loss formalism to study the mass hierarchy in heavy flavor suppression. We present i) Analytical derivation of a direct relation between collisional suppression/energy loss and heavy quark mass. ii) A novel observable sensitive only to the collisional energy loss mechanism to be tested by future high-precision experiments. iii) Analytical and numerical extraction of the mass hierarchy in collisional energy losses through this observable.