Dijet Asymmetry in the Resummation Improved Perturbative QCD Approach

TL;DR

This paper introduces a systematic theoretical framework combining perturbative QCD and Sudakov resummation to accurately describe dijet asymmetries in hadron collisions, matching experimental data and extracting medium properties.

Contribution

It develops the first resummation improved pQCD approach for dijet asymmetries, enhancing theoretical precision near kinematic endpoints.

Findings

Good agreement with ATLAS dijet asymmetry data

Extraction of jet transport coefficient $\

Demonstrates the importance of combined pQCD and Sudakov resummation methods.

Abstract

We develop the first systematic theoretical approach to dijet asymmetries in hadron-hadron collisions based on the perturbative QCD (pQCD) expansion and the Sudakov resummation formalism. We find that the pQCD calculation at next-to-leading order is indispensable to describe the experimental data, while the Sudakov resummation formalism is vital near the end points where the pQCD expansion fails to converge due to the appearance of large Sudakov logarithms. Utilizing our resummation improved pQCD approach, we obtain good agreement with the most up-to-date fully corrected ATLAS data on dijet asymmetry in $pp$ collisions. Combining with the BDMPS jet energy loss formalism, we extract the value of jet transport coefficient $\hat{q}_0 \sim 2$-$6~\textrm{GeV}^2/\textrm{fm}$ for the quark-gluon-plasma created in $PbPb$ collisions at 2.76A TeV. This work paves the way for a more complete and deeper understanding of the properties of strongly-coupled QCD medium via the studies of dijet asymmetries in relativistic heavy-ion collisions.