Measurement of Angular Distributions of Drell-Yan Dimuons in p plus p Interactions at 800 GeV/c

作者：Zhu L Y^*; Peng J C; Reimer P E; Awes T C; Brooks M L; Brown C N; Bush J D; Carey T A; Chang T H; Cooper W E; Gagliardi C A; Garvey G T; Geesaman D F; Hawker E A; He X C; Isenhower L D; Kaplan D M; Kaufman S B; Klinksiek S A; Koetke D D; Lee D M; Lee W M; Leitch M J; Makins N; McGaughey P L; Moss J M; Mueller B A; Nord P M; Papavassiliou V; Park B K; Petitt G; Sadler M E; Sondheim W E; Stankus P W

来源：Physical Review Letters, 2009, 102(18): 182001.

DOI：10.1103/PhysRevLett.102.182001

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 < m(mu mu)< 15 GeV/c(2) (excluding the Upsilon resonance region), 0 < p(T)< 4 GeV/c, and 0 < x(F)< 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 phi distribution either to the presence of the transverse-momentum-dependent Boer-Mulders structure function h(1)(perpendicular to) 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.

• 出版日期2009-5-8
• 单位Los Alamos