Drell-Yan Angular Distributions at the E906 SeaQuest Experiment

Measurement of Drell-Yan angular distributions in the Collins-Soper frame provide a unique study of QCD. Previous experimental results showed a violation of the Lam-Tung relation (1 – $\lambda$ $\neq$ 2$\nu$). This violation could be described by a range of non-perturbative effects, including the naive T-odd Boer-Mulders TMD, which describes spin-momentum correlations in the nucleon. Presently, E906/SeaQuest experiment at Fermilab can measure Drell-Yan dimuon pairs produced from a 120 GeV unpolarized proton beam directed on various nuclear targets. The Drell-Yan angular distributions will be measured at higher-x than previous experiments, further disentangling the role the Boer-Mulders TMD and other non-perturbative effects play in the structure of the nucleon.