Speaker
Description
The study of the spin structure of the nucleon by measuring nucleon spin (in)dependent azimuthal asymmetries in Drell-Yan process is one of the main topics of the phase-II research programme of the COMPASS experiment (M2 beamline, SPS, CERN).
In 2015 and 2018 COMPASS performed Drell-Yan measurements using a 190 GeV $\pi^-$ beam interacting with a transversely polarized $NH_3$ and unpolarized nuclear targets. The angular coefficients \lambda, \mu and \nu that describe the unpolarized part of the Drell-Yan cross section have been extracted from the data collected with tungsten target. Obtained results provide important information to study various perturbative and non-perturbative QCD effects. Performed polarized measurements of the Sivers and other transverse azimuthal asymmetries in Drell-Yan provide a unique possibility to test predicted in QCD (pseudo-)universal features of related transverse momentum dependent parton distribution functions. Measurement of the same set of asymmetries in J/$\psi$ production gives access to the gluon parton distribution functions and may serve as an important input for the study of J/$\psi$ production mechanisms.
In this talk recent results from COMPASS Drell-Yan programme will be presented together with related measurements from other experiments and available model predictions.
| Submitted on behalf of a Collaboration? | Yes |
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