Jets In Heavy Ion Collisions with CMS

Sevil Salur

doi:10.1088/1742-6596/736/1/012004

Abstract

Jet physics in heavy ion collisions is a rich field which has been rapidly evolving since the first observations of medium interactions at RHIC through back-to-back hadron correlations and at LHC via reconstructed jets. In order to completely characterize the final state via jet-medium interactions and distinguish between competing energy loss mechanisms, complementary and robust jet observables are investigated. Latest developments of jet finding techniques and their applications to heavy ion environments are discussed with an emphasis given on experimental results from CMS experiment.

Highlights

Well identified decay products of partonic interactions at large momentum transfers, called hard probes, are used to study the structure and dynamics of the QGP that is produced in heavy ion collisions [1, 2, 3]
We summarize the more recent jet measurements in heavy ion collisions that are collected during the Run 1 period of LHC data taking with the CMS experiment
Particle Flow (PF) objects that are reconstructed by combining information from various sub-detectors, most importantly by combining tracks with clusters in electromagnetic and hadronic calorimeters [18] and only calorimetric measurements from HCAL and ECAL are used as inputs to the jet reconstruction algorithms

Summary

Introduction

Well identified decay products of partonic interactions at large momentum transfers, called hard probes, are used to study the structure and dynamics of the QGP that is produced in heavy ion collisions [1, 2, 3]. The most common hard probe of QCD, are collimated sprays of hadronic decay products of hard-scattered partons. They are experimental signatures of quarks and gluons and are expected to reflect kinematics and topology of the initial hard scattered partons. Due to its scale dependence, the definition of the parton is ambiguous, resulting in different jet definitions corresponding to various jet reconstruction algorithms. For an acceptable jet algorithm, the main requirement is to merge measured particles to form a jet in a procedure that matches the theoretical calculations without a strong dependence on modeling [8]. The algorithm must be insensitive to soft and collinear radiation i.e., infrared and collinear safety with a seedless implementation for data analysis

Methods

Findings

Conclusion