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1.
Phys Rev Lett ; 102(18): 182001, 2009 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-19518860

RESUMO

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5

2.
Phys Rev Lett ; 100(6): 062301, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18352463

RESUMO

We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0

4.
Phys Rev Lett ; 91(21): 211801, 2003 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-14683289

RESUMO

We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).

5.
Phys Rev Lett ; 86(12): 2529-32, 2001 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-11289972

RESUMO

We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at square root of s = 38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state shows no polarization at small values of the fractional longitudinal momentum x(F) and transverse momentum p(T) but significant positive transverse production polarization for either p(T)>1.8 GeV/c or for x(F)>0.35. The Upsilon(2S+3S) (unresolved) states show a large transverse production polarization at all values of x(F) and p(T) measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.

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