Measurement of Angular Distributions of Drell-Yan Dimuons Inp+dinteractions At800 GeV/c

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an $800\text{ }\text{ }\mathrm{GeV}/c$ proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range $4.5<{m}_{\ensuremath{\mu}\ensuremath{\mu}}<15\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, $0<{p}_{T}<4\text{ }\text{ }\mathrm{GeV}/c$, and $0<{x}_{F}<0.8$. No significant $\mathrm{cos}2\ensuremath{\phi}$ dependence is found in these proton-induced Drell-Yan data, in contrast with the situation for pion-induced Drell-Yan data. The data are compared with expectations from models which attribute the $\mathrm{cos}2\ensuremath{\phi}$ distribution to a QCD vacuum effect or to the presence of the transverse-momentum-dependent Boer-Mulders structure function ${h}_{1}^{\ensuremath{\perp}}$. Constraints on the magnitude of the sea-quark ${h}_{1}^{\ensuremath{\perp}}$ structure functions are obtained.