Recent measurement of Delta G/G at COMPASS

We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polari...

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Detalles Bibliográficos
Autor principal: Bernet, Colin
Lenguaje:eng
Publicado: 2005
Materias:
Particle Physics - Experiment
Acceso en línea:https://dx.doi.org/10.1063/1.2122209
http://cds.cern.ch/record/853046
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author Bernet, Colin
author_facet Bernet, Colin
author_sort Bernet, Colin
collection CERN
description We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.
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spelling cern-8530462023-03-14T19:12:42Zdoi:10.1063/1.2122209http://cds.cern.ch/record/853046engBernet, ColinRecent measurement of Delta G/G at COMPASSParticle Physics - ExperimentWe present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.We present a preliminary measurement of the gluon polarization ΔG/G in the nucleon, based on the spin asymmetry of quasi‐real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A∥/D = 0.002 ± 0.019(stat.) ± 0.003(exp.syst.). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon ΔG/G(xg = 0.095, μ2 = 3 GeV2) = 0.024 ± 0.089(stat.) ± 0.057(syst.). This value is consistent with parameterizations obtained from QCD fits to the g1 data, with a first moment ΔG ≡ ∫01 ΔG(x)dx ≃ 0.5, at the same scale.We present a preliminary measurement of the gluon polarization Delta G/G in the nucleon, based on the spin asymmetry of quasi-real photoproduction events for which a pair of large transverse momentum hadrons is produced. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a large polarized 6LiD target. The preliminary helicity asymmetry for the selected events is A_||/D = 0.002 +- 0.019(stat) +- 0.003(syst). From this value, a leading order analysis based on the model of PYTHIA leads to the gluon polarization in the nucleon Delta G/G(x_g=0.095, mu^2=3 GeV^2)=0.024 +- 0.089(stat) +- 0.057(syst). This value is consistent with parameterizations obtained from QCD fits to the g_1 data, with a first moment Delta G lower than 1, at the same scale.hep-ex/0507049oai:cds.cern.ch:8530462005-07-11
spellingShingle Particle Physics - Experiment
Bernet, Colin
Recent measurement of Delta G/G at COMPASS
title Recent measurement of Delta G/G at COMPASS
title_full Recent measurement of Delta G/G at COMPASS
title_fullStr Recent measurement of Delta G/G at COMPASS
title_full_unstemmed Recent measurement of Delta G/G at COMPASS
title_short Recent measurement of Delta G/G at COMPASS
title_sort recent measurement of delta g/g at compass
topic Particle Physics - Experiment
url https://dx.doi.org/10.1063/1.2122209
http://cds.cern.ch/record/853046
work_keys_str_mv AT bernetcolin recentmeasurementofdeltaggatcompass

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