Speaker
Description
The partonic structure of the pion remains poorly understood due to the lack of direct pion targets. Current global fits of the pion parton distribution functions (PDFs) rely primarily on decades-old fixed-target Drell-Yan experiments (NA10 and E615), which are mostly sensitive to valence quarks. The CERN COMPASS experiment has provided new data by measuring Drell-Yan production using a 190 GeV/c π− beam incident on a transversely polarized NH3 target, as well as nuclear alumina and tungsten targets, in 2015 and 2018. The use of the light NH3 target offers the advantage of reduced nuclear effects in the extraction of pion PDFs. We report differential cross sections for pion-induced Drell-Yan production in the kinematic ranges of Feynman-xF = −0.2 to 0.9 and transverse momentum pT=0.0 to 3.6 GeV/c. In this talk, preliminary cross-section results will be presented and compared with fixed-order QCD calculations using various pion PDF sets. The kinematic dependence of nuclear effects in Drell-Yan production will also be examined by comparing cross sections obtained from the three different targets.
