Bayesian Extraction of Jet Energy Loss Distributions in Heavy-Ion Collisions
Yayun He1,2, Long-Gang Pang2,3, Xin-Nian Wang1,2,3
1Key Laboratory of Quark & Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079, China.
Physical Review Letters
|July 27, 2019
Summary
Researchers analyzed jet energy loss in heavy-ion collisions using perturbative quantum chromodynamics and Monte Carlo methods. They extracted jet energy loss distributions, finding they decrease with collision centrality and are consistent with transport model simulations.
Area of Science:
- High Energy Nuclear Physics
- Quantum Chromodynamics (QCD)
- Particle Physics
Background:
- Jet production in heavy-ion collisions is crucial for understanding the quark-gluon plasma.
- Perturbative QCD provides a framework to describe jet cross-sections, incorporating energy loss.
- Experimental data from the Large Hadron Collider (LHC) offer insights into jet quenching phenomena.
Purpose of the Study:
- To extract jet energy loss distributions from experimental data in lead-lead (Pb+Pb) collisions.
- To investigate the dependence of jet energy loss on initial jet energy and collision centrality.
- To compare extracted distributions with theoretical models, specifically the linear Boltzmann transport model.
Main Methods:
- Utilized a factorization approach based on perturbative QCD relating heavy-ion and proton-proton jet cross-sections.
- Employed the Markov Chain Monte Carlo (MCMC) method for Bayesian analysis of experimental jet spectra.
- Analyzed data for single inclusive and gamma-triggered jets at different centralities and LHC energies.
Main Results:
- Extracted energy loss distributions for jets in Pb+Pb collisions.
- Observed that average jet energy loss depends slightly stronger than logarithmically on initial jet energy.
- Found that jet energy loss decreases from central to peripheral collisions and distributions exhibit scaling behavior with large widths.
Conclusions:
- The extracted jet energy loss distributions are consistent with simulations from the linear Boltzmann transport model.
- Jet quenching in these collisions is attributed to a limited number of out-of-cone scatterings on average.
- The study provides valuable constraints on models of hot and dense nuclear matter created at the LHC.
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