Decomposing transverse momentum balance contributions for quenched jets in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

TL;DR

This paper investigates how jets lose energy in the quark-gluon plasma by analyzing the angular distribution of charged particles' transverse momentum in PbPb collisions compared to pp collisions, revealing detailed contributions to jet quenching.

Contribution

It introduces a decomposition method for transverse momentum balance contributions, distinguishing short-range jet peaks from long-range azimuthal asymmetries in heavy ion collisions.

Findings

Charged-particle pt contributions vary with collision centrality and pt.

Long-range azimuthal asymmetries are significant in PbPb collisions.

Results differ notably from pp collision baseline.

Abstract

Interactions between jets and the quark-gluon plasma produced in heavy ion collisions are studied via the angular distributions of summed charged-particle transverse momenta (pt) with respect to both the leading and subleading jet axes in high-pt dijet events. The contributions of charged particles in different momentum ranges to the overall event pt balance are decomposed into short-range jet peaks and a long-range azimuthal asymmetry in charged-particle pt. The results for PbPb collisions are compared to those in pp collisions using data collected in 2011 and 2013, at collision energy sqrt(s[NN]) = 2.76 TeV with integrated luminosities of 166 inverse microbarns and 5.3 inverse picobarns, respectively, by the CMS experiment at the LHC. Measurements are presented as functions of PbPb collision centrality, charged-particle pt, relative azimuth, and radial distance from the jet axis for balanced and unbalanced dijets.