Jet Observables of Parton Energy Loss in High-Energy Nuclear Collisions

TL;DR

This paper discusses recent theoretical advances in understanding jet shapes and cross sections affected by parton energy loss in quark-gluon plasma, highlighting the potential of jet observables for detailed medium characterization.

Contribution

It introduces a new theoretical model for intra-jet energy flow and demonstrates how jet suppression varies with cone size and energy cuts, enhancing jet tomography capabilities.

Findings

Jet suppression factor $R_{AA}$ varies with jet cone size and energy acceptance.

Jet broadening effects are subtle and mainly observed at the periphery of small cones.

The model provides a more differential approach to probe the QGP properties.

Abstract

While strong attenuation of single particle production and particle correlations has provided convincing evidence for large parton energy loss in the QGP, its application to jet tomography has inherent limitations due to the inclusive nature of the measurements. Generalization of this suppression to full jet observables leads to an unbiased, more differential and thus powerful approach to determining the characteristics of the hot QCD medium created in high-energy nuclear collisions. In this article we report on recent theoretical progress in calculating jet shapes and the related jet cross sections in the presence of QGP-induced parton energy loss. (i) A theoretical model of intra-jet energy flow in heavy-ion collisions is discussed. (ii) Realistic numerical simulations demonstrate the nuclear modification factor $R_{AA}(p_T)$ evolves continuously with the jet cone size $R^{\max}$ or the acceptance cut $\omega_{\min}$ - a novel feature of jet quenching. The anticipated broadening of jets is subtle and most readily manifested in the periphery of the cone for smaller cone radii.