Measurement of target spin (In)dependent asymmetries in dimuon production in pion-nucleon collisions at COMPASS

In 2015 and 2018, COMPASS performed Drell-Yan measurements using a 190 GeV π^- beam interacting with a transversely polarized NH₃ and unpolarized nuclear targets. The angular coefficients that describe the unpolarized part of the Drell-Yan cross section were extracted from the data collected with a tungsten target. The results obtained provide important information for the study of various perturbative and non-perturbative QCD effects. The performed polarized measurements of the Sivers and other transverse-spin azimuthal asymmetries in Drell-Yan provide a unique opportunity to test the (pseudo-)universality of transverse-momentum dependent parton distribution functions. Measuring the same set of asymmetries in J/ψ production may give an alternative access to parton distribution functions and serve as input for the study of J/ψ production mechanisms. (author)