Jet reconstruction in heavy ion collisions (emphasis on Underlying Event background subtraction)

TL;DR

This paper discusses the challenges of jet reconstruction in heavy-ion collisions, focusing on the impact of the dense Quark Gluon Plasma medium and the importance of background subtraction for accurate measurements at LHC.

Contribution

It highlights the significance of underlying event background subtraction in jet reconstruction within heavy-ion collisions and analyzes its effects on jet spectrum and fragmentation functions.

Findings

Underlying event background significantly affects jet measurements in A+A collisions.

Proper background subtraction is crucial for accurate jet spectrum and fragmentation analysis.

The dense medium modifies jet structures, complicating their reconstruction.

Abstract

A modification of the internal structure of jets is expected due to the production of a dense QCD medium, the Quark Gluon Plasma, in heavy-ion collisions. We discuss some aspects of jet reconstruction in p+p and A+A collisions and emphasize the dramatically increased contribution of the underlying event in nucleus-nucleus collisions as compared with the vacuum case. We conclude with its consequences on the full jet spectrum and fragmentation function extraction at LHC.