How robust is a thermal photon interpretation of the ALICE low-p_T data?

We present a rigorous theoretical analysis of the ALICE measurement of low-p_T direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of \sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different i...

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Detalles Bibliográficos
Autores principales: Klasen, M, Klein-Boesing, C, Koenig, F, Wessels, J P
Lenguaje:eng
Publicado: 2013
Materias:
Particle Physics - Phenomenology
Acceso en línea:https://dx.doi.org/10.1007/JHEP10(2013)119
http://cds.cern.ch/record/1565050
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author Klasen, M
Klein-Boesing, C
Koenig, F
Wessels, J P
author_facet Klasen, M
Klein-Boesing, C
Koenig, F
Wessels, J P
author_sort Klasen, M
collection CERN
description We present a rigorous theoretical analysis of the ALICE measurement of low-p_T direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of \sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find T = 304 \pm 58 MeV and 309 \pm 64 MeV for the effective temperature of the quark-gluon plasma (or hot medium) at p_T \in [0.8;2.2] GeV and p_T \in [1.5;3.5] GeV as well as a power-law (p_T^{-4}) behavior for p_T > 4 GeV as predicted by QCD hard scattering.
id cern-1565050
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2013
record_format invenio
spelling cern-15650502021-05-03T20:01:43Zdoi:10.1007/JHEP10(2013)119http://cds.cern.ch/record/1565050engKlasen, MKlein-Boesing, CKoenig, FWessels, J PHow robust is a thermal photon interpretation of the ALICE low-p_T data?Particle Physics - PhenomenologyWe present a rigorous theoretical analysis of the ALICE measurement of low-p_T direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of \sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find T = 304 \pm 58 MeV and 309 \pm 64 MeV for the effective temperature of the quark-gluon plasma (or hot medium) at p_T \in [0.8;2.2] GeV and p_T \in [1.5;3.5] GeV as well as a power-law (p_T^{-4}) behavior for p_T > 4 GeV as predicted by QCD hard scattering.arXiv:1307.7034MS-TP-13-18oai:cds.cern.ch:15650502013-07-26
spellingShingle Particle Physics - Phenomenology
Klasen, M
Klein-Boesing, C
Koenig, F
Wessels, J P
How robust is a thermal photon interpretation of the ALICE low-p_T data?
title How robust is a thermal photon interpretation of the ALICE low-p_T data?
title_full How robust is a thermal photon interpretation of the ALICE low-p_T data?
title_fullStr How robust is a thermal photon interpretation of the ALICE low-p_T data?
title_full_unstemmed How robust is a thermal photon interpretation of the ALICE low-p_T data?
title_short How robust is a thermal photon interpretation of the ALICE low-p_T data?
title_sort how robust is a thermal photon interpretation of the alice low-p_t data?
topic Particle Physics - Phenomenology
url https://dx.doi.org/10.1007/JHEP10(2013)119
http://cds.cern.ch/record/1565050
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AT kleinboesingc howrobustisathermalphotoninterpretationofthealicelowptdata
AT koenigf howrobustisathermalphotoninterpretationofthealicelowptdata
AT wesselsjp howrobustisathermalphotoninterpretationofthealicelowptdata

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