Polarised Drell-Yan Process in the COMPASS Experiment

The COMPASS collaboration at CERN has been contributing to the knowledge of the nucleon structure and its description in terms of the transverse momentum dependent PDFs, accessed through the SIDIS process. In 2014/2015 the data taking was dedicated to the polarised Drell-Yan (DY) measurement with a negative pion beam and a transversely polarised proton target, as well as unpolarised nuclear targets. These data are now being analysed. One of the main goals is to verify the predicted sign change of the Sivers distribution function when accessed from DY with respect to SIDIS. The details on the experimental setup, the covered phase space, a preliminary first look into data distributions and predictions for the full data sample will be presented.