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Are flow measurements at SPS reliable?

Several heavy ion experiments at SPS have measured azimuthal distributions of particles with respect to the reaction plane. These distributions are deduced from two-particle azimuthal correlations under the assumption that they result solely from correlations with the reaction plane. In this paper,...

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Detalles Bibliográficos
Autores principales: Borghini, N, Dinh, M, Ollitrault, Jean Yves
Lenguaje:eng
Publicado: 2000
Materias:
Acceso en línea:https://dx.doi.org/10.1103/PhysRevC.62.034902
http://cds.cern.ch/record/434341
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author Borghini, N
Dinh, M
Ollitrault, Jean Yves
author_facet Borghini, N
Dinh, M
Ollitrault, Jean Yves
author_sort Borghini, N
collection CERN
description Several heavy ion experiments at SPS have measured azimuthal distributions of particles with respect to the reaction plane. These distributions are deduced from two-particle azimuthal correlations under the assumption that they result solely from correlations with the reaction plane. In this paper, we investigate other sources of azimuthal correlations: transverse momentum conservation, which produces back-to-back correlations, resonance decays, HBT correlations and final state interactions. These correlations increase with impact parameter: most of them vary with the multiplicity N like 1/N. When they are taken into account, the experimental results of the NA49 collaboration at SPS are significantly modified. These correlations might also explain an important fraction of the pion directed flow observed by WA98. Our analysis indicates that the methods currently used to measure the flow are not able to produce quantitative results.
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institution Organización Europea para la Investigación Nuclear
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spelling cern-4343412019-09-30T06:29:59Zdoi:10.1103/PhysRevC.62.034902http://cds.cern.ch/record/434341engBorghini, NDinh, MOllitrault, Jean YvesAre flow measurements at SPS reliable?Nuclear Physics - TheorySeveral heavy ion experiments at SPS have measured azimuthal distributions of particles with respect to the reaction plane. These distributions are deduced from two-particle azimuthal correlations under the assumption that they result solely from correlations with the reaction plane. In this paper, we investigate other sources of azimuthal correlations: transverse momentum conservation, which produces back-to-back correlations, resonance decays, HBT correlations and final state interactions. These correlations increase with impact parameter: most of them vary with the multiplicity N like 1/N. When they are taken into account, the experimental results of the NA49 collaboration at SPS are significantly modified. These correlations might also explain an important fraction of the pion directed flow observed by WA98. Our analysis indicates that the methods currently used to measure the flow are not able to produce quantitative results.nucl-th/0004026SACLAY-SPHT-T-2000-049oai:cds.cern.ch:4343412000-04-11
spellingShingle Nuclear Physics - Theory
Borghini, N
Dinh, M
Ollitrault, Jean Yves
Are flow measurements at SPS reliable?
title Are flow measurements at SPS reliable?
title_full Are flow measurements at SPS reliable?
title_fullStr Are flow measurements at SPS reliable?
title_full_unstemmed Are flow measurements at SPS reliable?
title_short Are flow measurements at SPS reliable?
title_sort are flow measurements at sps reliable?
topic Nuclear Physics - Theory
url https://dx.doi.org/10.1103/PhysRevC.62.034902
http://cds.cern.ch/record/434341
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