Pileup Correction on Higher-order Cumulants with Unfolding Approach

Abstract

Higher-order cumulants of conserved charge distributions are sensitive observables to probe the critical fluctuations near QCD critical point in heavy-ion collisions. Due to high interaction rate, pileup event can be one of the major sources of background in the measurements of higher-order cumulants. In this paper, we studied the effects of pileup events on higher-order cumulants of proton multiplicity distributions using UrQMD model. It is found that the proposed pileup correction fails if the correction parameters are determined by the Glauber fitting of charged particle multiplicities, which is usually done in the real heavy-ion experiment. To address this, we propose a model independent unfolding approach to determine the parameters in the pileup correction. This approach can be applied in the pileup correction for the future measurement of higher-order cumulants in heavy-ion collision experiment.

14 pages, 6 figures

References in corpus (5)

• The QCD Equation of State to $\mathcal{O}({\mu }_B^6)$ from Lattice QCD
• Scale for the Phase Diagram of Quantum Chromodynamics
• QCD phase transitions via a refined truncation of Dyson-Schwinger equations
• Lattice simulations of the QCD chiral transition at real baryon density
• Critical endpoint of QCD in a finite volume

Cited by in corpus (3)

• Search for the QCD Critical Point in High Energy Nuclear Collisions
• Higher-Order Cumulants and Correlation Functions of Proton Multiplicity Distributions in $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV Au+Au Collisions at the RHIC STAR Experiment
• Beam Energy Dependence of Fifth and Sixth-Order Net-proton Number Fluctuations in Au+Au Collisions at RHIC