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Title: Correlated stopping, proton clusters and higher order proton cumulants

Abstract

Here, we investigate possible effects of correlations between stopped nucleons on higher order proton cumulants at low energy heavy-ion collisions. We find that fluctuations of the number of wounded nucleons N part lead to rather nontrivial dependence of the correlations on the centrality; however, this effect is too small to explain the large and positive four-proton correlations found in the preliminary data collected by the STAR collaboration at √s = 7.7 GeV. We further demonstrate that, by taking into account additional proton clustering, we are able to qualitatively reproduce the preliminary experimental data. We speculate that this clustering may originate either from collective/multi-collision stopping which is expected to be effective at lower energies or from a possible first-order phase transition, or from (attractive) final state interactions. To test these ideas we propose to measure a mixed multi-particle correlation between stopped protons and a produced particle (e.g. pion, antiproton).

Authors:
 [1];  [2];  [3]
  1. AGH Univ. of Science and Technology, Krakow (Poland)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States). Riken BNL Research Center; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1371533
Alternate Identifier(s):
OSTI ID: 1379832
Report Number(s):
BNL-114044-2017-JA
Journal ID: ISSN 1434-6044; R&D Project: PO-3
Grant/Contract Number:
SC0012704; AC02-05CH11231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
European Physical Journal. C, Particles and Fields
Additional Journal Information:
Journal Volume: 77; Journal Issue: 5; Journal ID: ISSN 1434-6044
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Riken BNL Research Center

Citation Formats

Bzdak, Adam, Koch, Volker, and Skokov, Vladimir. Correlated stopping, proton clusters and higher order proton cumulants. United States: N. p., 2017. Web. doi:10.1140/epjc/s10052-017-4847-0.
Bzdak, Adam, Koch, Volker, & Skokov, Vladimir. Correlated stopping, proton clusters and higher order proton cumulants. United States. doi:10.1140/epjc/s10052-017-4847-0.
Bzdak, Adam, Koch, Volker, and Skokov, Vladimir. Fri . "Correlated stopping, proton clusters and higher order proton cumulants". United States. doi:10.1140/epjc/s10052-017-4847-0. https://www.osti.gov/servlets/purl/1371533.
@article{osti_1371533,
title = {Correlated stopping, proton clusters and higher order proton cumulants},
author = {Bzdak, Adam and Koch, Volker and Skokov, Vladimir},
abstractNote = {Here, we investigate possible effects of correlations between stopped nucleons on higher order proton cumulants at low energy heavy-ion collisions. We find that fluctuations of the number of wounded nucleons Npart lead to rather nontrivial dependence of the correlations on the centrality; however, this effect is too small to explain the large and positive four-proton correlations found in the preliminary data collected by the STAR collaboration at √s = 7.7 GeV. We further demonstrate that, by taking into account additional proton clustering, we are able to qualitatively reproduce the preliminary experimental data. We speculate that this clustering may originate either from collective/multi-collision stopping which is expected to be effective at lower energies or from a possible first-order phase transition, or from (attractive) final state interactions. To test these ideas we propose to measure a mixed multi-particle correlation between stopped protons and a produced particle (e.g. pion, antiproton).},
doi = {10.1140/epjc/s10052-017-4847-0},
journal = {European Physical Journal. C, Particles and Fields},
number = 5,
volume = 77,
place = {United States},
year = {Fri May 05 00:00:00 EDT 2017},
month = {Fri May 05 00:00:00 EDT 2017}
}

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Cited by: 3works
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  • © 2017, The Author(s). We investigate possible effects of correlations between stopped nucleons on higher order proton cumulants at low energy heavy-ion collisions. We find that fluctuations of the number of wounded nucleons N part lead to rather nontrivial dependence of the correlations on the centrality; however, this effect is too small to explain the large and positive four-proton correlations found in the preliminary data collected by the STAR collaboration at s=7.7 GeV. We further demonstrate that, by taking into account additional proton clustering, we are able to qualitatively reproduce the preliminary experimental data. We speculate that this clustering maymore » originate either from collective/multi-collision stopping which is expected to be effective at lower energies or from a possible first-order phase transition, or from (attractive) final state interactions. To test these ideas we propose to measure a mixed multi-particle correlation between stopped protons and a produced particle (e.g. pion, antiproton).« less
  • Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to themore » thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.« less
  • Cited by 25
  • The strongly correlated stopping of [ital N] pointlike charges organized in clusters with a regular geometry is thoroughly investigated at high velocity as a linear and binary superposition of the stopping of a dicluster polarized with respect to the overall drift velocity. For [ital N][ge]3, [ital a] priori unexpected [ital N]-body and collective behaviors are identified in terms of variations for the target electron density, cluster topology, charge distribution, and projectile velocity. The target is featured as a homogeneous and dense electron jellium quantified with the Wigner coupling parameters [ital r][sub [ital S]]. A corresponding dielectric function is taken inmore » a plasmon pole approximation, allowing for a quasianalytic and transparent analysis. A recurring trend of this study is an enhanced stopping due to charge correlation, increasing rapidly with [ital N]. A noticeable counterexample is afforded by a regular [ital N] chain of charges flowing parallel to its velocity. As a rule, in most practical cases of interest, correlated charges within a few atomic interdistances can experience a stopping that is enhanced by orders of magnitudes relative to the isolated charge case, when stopped in a target at ordinary matter density, with initial kinetic energy in the tens of keV/amu range.« less