Cross Section and Parity-Violating Spin Asymmetries of W(+/-) Boson Production in Polarized p plus p Collisions at root s=500 Gev
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
18/04/2012
18/04/2012
2011
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Resumo |
Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = 0.86(-0.14)(+0.30) and Ae(L)(e-) = 0.88(-0.71)(+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p + p collisions at a center-of-mass energy of root s = 500 GeV with the PHENIX detector at RHIC. These e(+/-) come mainly from the decay of W(+/-) and Z(0) bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W(+/-) to the light quarks. The observed electron and positron yields were used to estimate W(+/-) boson production cross sections for the e(+/-) channels of sigma(pp -> W(+)X) X BR(W(+) -> e(+) nu(e)) = 144.1 +/- 21.2(stat)(-10.3)(+3.4)(syst) +/- 21.6(norm) pb, and sigma(pp -> W(-)X) X BR(W(-) -> e(-) (nu) over bar (e)) = 3.17 +/- 12.1(stat)(-8.2)(+10.1)(syst) +/- 4.8(norm) pb. Office of Nuclear Physics in DOE Office of Science National Science Foundation NSF (USA) MEXT (Japan) JSPS - Japan Society for the Promotion of Science (Japan) CNPq (Brazil) FAPESP (Brazil) NSFC (China) MSMT (Czech Republic) Centre National de la Recherche Scientifique - IN2P3/CNRS (France) CEA (France) BMBF - Bundesministerium fur Bildung und Forschung, Germany (DAAD) Deutscher Akademischer Austausch Dienst, Germany Alexander von Humboldt Foundation (Germany) OTKA (Hungary) (DAE) Department of Atomic Energy, India (DST) Department of Science and Technology, India ISF - Israel Science Foundation (Israel) NRF (Korea) WCU (Korea) MES Ministry of Education and Science of the Russian Federation RAS Russia Academy of Sciences FAAE (Russia) VR (Sweden) KAW (Sweden) U.S. CRDF for the FSU Hungary-U.S. HAESF (BSF) US-Israel Binational Science Foundation |
Identificador |
PHYSICAL REVIEW LETTERS, v.106, n.6, 2011 0031-9007 http://producao.usp.br/handle/BDPI/16059 10.1103/PhysRevLett.106.062001 |
Idioma(s) |
eng |
Publicador |
AMER PHYSICAL SOC |
Relação |
Physical Review Letters |
Direitos |
restrictedAccess Copyright AMER PHYSICAL SOC |
Palavras-Chave | #PARTON DISTRIBUTIONS #PHYSICS #SCATTERING #PROTON #Physics, Multidisciplinary |
Tipo |
article original article publishedVersion |