Speaker
Dr
Michela Chiosso
(INFN, Sezione di Torino and University of Torino)
Description
Much of the information that exists today about Transverse Momentum
Dependent Parton Distribution Functions (TMDs) comes from SIDIS
measurements with unpolarised and polarised beams and targets where they appear convoluted with fragmentation functions (FFs).
Drell-Yan (DY)measurements are complementary to those by SIDIS experiments, as they allow to measure convolutions of only PDFs without involving FFs. Moreover, given the T-odd character of both Sivers and Boer-Mulders functions, the sign of these TMDs is expected to be reversed when observed from SIDIS or from DY.
Measurements of SIDIS were performed by Compass in the period 2002 to
2007 and in 2010, using a naturally polarised m+ beam and a solid state target polarised either longitudinally or transversely with respect to the beam direction. Now the COMPASS-II Experiment has the unique opportunity to access TMDs also from single-polarised Drell-Yan processes, allowing to test the sign change prediction for the first time. We present here the future polarised DY measurements at COMPASS-II, which are foreseen to start in late 2014.
Author
Dr
Michela Chiosso
(INFN, Sezione di Torino and University of Torino)
