Towards the understanding of jet shapes and cross sections in heavy ion collisions using soft-collinear effective theory

TL;DR

This paper uses soft-collinear effective theory to systematically analyze jet shapes and cross sections in heavy ion collisions, incorporating medium effects and providing quantitative predictions for LHC experiments.

Contribution

It extends SCET with Glauber gluons to include medium modifications, enabling precise calculations of jet observables in heavy ion collisions.

Findings

Quantitative understanding of jet shape modifications in Pb-Pb collisions.

Predictions for jet shape and cross section at higher LHC energies.

Analysis of jet suppression dependence on centrality, radius, and kinematics.

Abstract

We calculate the jet shape and the jet cross section in heavy ion collisions using soft-collinear effective theory (SCET) and its extension with Glauber gluon interactions in the medium (SCET$_{\rm G}$). We use the previously developed framework to systematically resum the jet shape at next-to-leading logarithmic accuracy, and we consistently include the medium modification by incorporating the leading order medium-induced splitting functions. The calculation provides, for the first time, a quantitative understanding of the jet shape modification measurement in lead-lead collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV at the LHC. The inclusive jet suppression is also calculated within the same framework beyond the traditional concept of parton energy loss, and the dependence on the centrality, the jet radius and the jet kinematics is examined. In the end we present predictions for the anticipated jet shape and cross section measurements in lead-lead collisions at $\sqrt{s_{\rm NN}}\approx5.1$ TeV at the LHC.