We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5<mμμ<15GeV/c2 (excluding the Υ resonance region), 0<pT<4GeV/c, and 0<xF<0.8. The p+p angular distributions are similar to those of p+d, and both data sets are compared with models which attribute the cos2 distribution either to the presence of the transverse-momentum- dependent Boer-Mulders structure function h1 or to QCD effects. The data indicate the need to include QCD effects before reliable information on the Boer-Mulders function can be extracted. The validity of the Lam-Tung relation in p+p Drell-Yan data is also tested.
ASJC Scopus subject areas
- Physics and Astronomy(all)