Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at s=200 GeV
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
18/04/2012
18/04/2012
2009
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Resumo |
We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive pi(0) production at midrapidity in polarized proton collisions at s=200 GeV. The cross section was measured over a transverse momentum range of 1 < p(T)< 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p(T)< 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of pi(0)'s in their parent jets was found to be around 0.7 for electromagnetically triggered events. U. S. NSF National Science Foundation Sloan Foundation, Deutsche Forschungsgemeinschaft - DFG Centre National de la Recherche Scientifique - CNRS/IN2P3 STFC EPSRC of the United Kingdom FAPESP CNPq of Brazil MES Ministry of Ed. and Sci. of the Russian Federation National Natural Science Foundation of China (NNSFC) CAS of China MoST of China MoE of China MSMT of the Czech Republic FOM of the Netherlands NWO of the Netherlands (DAE) Department of Atomic Energy, India (DST) Department of Science and Technology, India (CSIR) Council of Scientific and Industrial Research - India Polish Ministry of Science and Higher Education Korea Research Foundation (KRF) Ministry of Science, Education, and Sports of the Republic of Croatia MES Russian Ministry of Science and Technology RosAtom of Russia |
Identificador |
PHYSICAL REVIEW D, v.80, n.11, 2009 1550-7998 http://producao.usp.br/handle/BDPI/16313 10.1103/PhysRevD.80.111108 |
Idioma(s) |
eng |
Publicador |
AMER PHYSICAL SOC |
Relação |
Physical Review D |
Direitos |
restrictedAccess Copyright AMER PHYSICAL SOC |
Palavras-Chave | #PARTON DISTRIBUTIONS #NUCLEON #PHOTOPRODUCTION #MOMENTUM #HADRONS #JET #Astronomy & Astrophysics #Physics, Particles & Fields |
Tipo |
article original article publishedVersion |