Study of transverse momentum dependent distributions from polarised Drell-Yan at COMPASS

The Parton Distributions Functions (PDFs) and the spin structure of the nucleon are studied by the COMPASS experiment at CERN. The transverse momentum dependent (TMD) PDFs of the proton will be accessed via Drell-Yan (DY) dimuon production in negative pion collisions on a NH_3 transversely polarised target. From this measurement the dimuon azimuthal asymmetries will be extracted, that can be related to 4 TMDs known as transversity, pretzelosity, Sivers and Boer-Mulders. The latter 2 TMDs are time-reversal odd distributions and are expected to change their sign when compared with the ones obtained from Semi-Inclusive Deep Inelastic Scattering, also studied in COMPASS. We aim at performing the first polarised DY measurement starting in 2014.