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Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions
Assuming that the final state of hadronization takes place along the freezeout line, which is defined by a constant entropy density, the antiproton-to-proton ratios produced in heavy-ion collisions are studied in framework of the hadron resonance gas (HRG) model. A phase transition from quark--gluon...
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Lenguaje: | eng |
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2010
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Acceso en línea: | http://cds.cern.ch/record/1310061 |
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author | Tawfik, A |
author_facet | Tawfik, A |
author_sort | Tawfik, A |
collection | CERN |
description | Assuming that the final state of hadronization takes place along the freezeout line, which is defined by a constant entropy density, the antiproton-to-proton ratios produced in heavy-ion collisions are studied in framework of the hadron resonance gas (HRG) model. A phase transition from quark--gluon plasma to hadrons, a hadronization, has been conjectured in order to allow modifications in the phase space volume and thus in single--particle distribution function. Implementing both modifications in the grand--canonical partition function and taking into account the experimental acceptance in heavy-ion collisions, the antiproton-to-proton ratios over center-of-mass energies $\sqrt{s}$ ranging from AGS to RHIC are very well reproduced by the HRG model. Comparing with the same particle ratios in $pp$ collisions results in a gradually narrowing discrepancy with increasing $\sqrt{s}$. At LHC energy, the ALICE antiproton-to-proton ratios in $pp$ collisions turn to be very well described by HRG model as well. It is likely that the ALICE heavy-ion program will produce the same antiproton-to-proton ratios as the $pp$ program. Furthermore, the ratio gets very close to unity indicating that the matter-antimatter asymmetry nearly vanishes. The chemical potential calculated at this energy strengthens the assumption of almost fully matter-antimatter symmetry at LHC energy. |
id | cern-1310061 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2010 |
record_format | invenio |
spelling | cern-13100612019-09-30T06:29:59Zhttp://cds.cern.ch/record/1310061engTawfik, AAntiproton-to-Proton Ratios for ALICE Heavy-Ion CollisionsParticle Physics - PhenomenologyAssuming that the final state of hadronization takes place along the freezeout line, which is defined by a constant entropy density, the antiproton-to-proton ratios produced in heavy-ion collisions are studied in framework of the hadron resonance gas (HRG) model. A phase transition from quark--gluon plasma to hadrons, a hadronization, has been conjectured in order to allow modifications in the phase space volume and thus in single--particle distribution function. Implementing both modifications in the grand--canonical partition function and taking into account the experimental acceptance in heavy-ion collisions, the antiproton-to-proton ratios over center-of-mass energies $\sqrt{s}$ ranging from AGS to RHIC are very well reproduced by the HRG model. Comparing with the same particle ratios in $pp$ collisions results in a gradually narrowing discrepancy with increasing $\sqrt{s}$. At LHC energy, the ALICE antiproton-to-proton ratios in $pp$ collisions turn to be very well described by HRG model as well. It is likely that the ALICE heavy-ion program will produce the same antiproton-to-proton ratios as the $pp$ program. Furthermore, the ratio gets very close to unity indicating that the matter-antimatter asymmetry nearly vanishes. The chemical potential calculated at this energy strengthens the assumption of almost fully matter-antimatter symmetry at LHC energy.arXiv:1011.5612ECTP-2010-11oai:cds.cern.ch:13100612010-11-29 |
spellingShingle | Particle Physics - Phenomenology Tawfik, A Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title | Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title_full | Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title_fullStr | Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title_full_unstemmed | Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title_short | Antiproton-to-Proton Ratios for ALICE Heavy-Ion Collisions |
title_sort | antiproton-to-proton ratios for alice heavy-ion collisions |
topic | Particle Physics - Phenomenology |
url | http://cds.cern.ch/record/1310061 |
work_keys_str_mv | AT tawfika antiprotontoprotonratiosforaliceheavyioncollisions |