Transverse single-spin asymmetry and cross section for pi(0) and eta mesons at large Feynman x in p(up arrow) + p collisions at root s=200 GeV
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
05/11/2013
05/11/2013
2012
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Resumo |
Measurements of the differential cross section and the transverse single-spin asymmetry, A(N), vs x(F) for pi(0) and eta mesons are reported for 0.4 < x(F) < 0.75 at an average pseudorapidity of 3.68. A data sample of approximately 6.3 pb(-1) was analyzed, which was recorded during p(up arrow) + p collisions at root s = 200 GeV by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross section for pi(0), including the previously unmeasured region of x(F) > 0.55, is consistent with a perturbative QCD prediction, and the eta/pi(0) cross-section ratio agrees with existing midrapidity measurements. For 0.55 < x(F) < 0.75, the average A(N) for eta is 0.210 +/- 0.056, and that for pi(0) is 0.081 +/- 0.016. The probability that these two asymmetries are equal is similar to 3%. RHIC Operations Group and RCF at BNL RHIC Operations Group and RCF at BNL NERSC Center at LBNL NERSC Center at LBNL Open Science Grid consortium Open Science Grid consortium Offices of NP and HEP within the U.S. DOE Office of Science Offices of NP and HEP within the U.S. DOE Office of Science U.S. NSF U.S. NSF Sloan Foundation Sloan Foundation Renaissance Technologies Corporation Renaissance Technologies Corporation DFG cluster of excellence Origin and Structure of the Universe of Germany DFG cluster of excellence "Origin and Structure of the Universe'' of Germany FAPESP CNPq of Brazil FAPESP CNPq of Brazil Ministry of Education and Science of the Russian Federation Ministry of Education and Science of the Russian Federation NNSFC NNSFC CAS CAS MoST MoST MoE of China MoE of China GA and MSMT of the Czech Republic GA and MSMT of the Czech Republic FOM and NWO of the Netherlands FOM and NWO of the Netherlands DAE DAE DST DST CSIR of India CSIR of India Polish Ministry of Science and Higher Education Polish Ministry of Science and Higher Education Korea Research Foundation Korea Research Foundation Ministry of Science, Education and Sports of the Republic of Croatia Ministry of Science, Education and Sports of the Republic of Croatia RosAtom of Russia RosAtom of Russia CNRS/IN2P3 CNRS/IN2P3 |
Identificador |
PHYSICAL REVIEW D, COLLEGE PK, v. 86, n. 5, supl. 2, Part 3, pp. 1370-1375, SEP 5, 2012 1550-7998 http://www.producao.usp.br/handle/BDPI/41832 10.1103/PhysRevD.86.051101 |
Idioma(s) |
eng |
Publicador |
AMER PHYSICAL SOC COLLEGE PK |
Relação |
PHYSICAL REVIEW D |
Direitos |
openAccess Copyright AMER PHYSICAL SOC |
Palavras-Chave | #FRAGMENTATION #POLARIZATION #GEV/C #BEAM #ASTRONOMY & ASTROPHYSICS #PHYSICS, PARTICLES & FIELDS |
Tipo |
article original article publishedVersion |