Nuclear effects on the nucleon structure functions in hadronic high-mass dimuon production

Pion transverse momentum dependent parton distributions in a light-front constituent approach, and the Boer-Mulders effect in the pion-induced Drell-Yan process

“…The used convention is such that x 1 describes the momentum fraction of the parton from π − , while x 2 describes the momentum fraction of the parton from the nucleon bound in the nucleus. In order to describe nuclei with proton number Z and neutron number N we will neglect nuclear binding effects and assume that, for instance, f 3 GeV [14,16], which includes the kinematic region of interest for our study.…”

“…At this point it is worth recalling that we neglect nuclear binding effects, which is justified for q T 3 GeV [14,16]. Thus, nuclear effects become important only beyond the range of q T we are interested in.…”

“…DY experiments with pions were reported in Refs. [11][12][13][14][15][16], see [17] for a compilation of DY data till 1993 and [18][19][20][21][22] for reviews of later data and theoretical progress. TMDs describe hard processes like DY on the basis of factorization theorems [23][24][25][26].…”

EMC effect in the Drell-Yan process at COMPASS

“…Apart of numerous deep inelastic experiments, the EMC effect has also been experimentally verified in the time-like region using both the pion-and the proton-induced Drell-Yan reactions in the E772 [6], E866 [7], NA3 [8], and NA10 [9] experiments. In the Drell-Yan process a quark (anti-quark) with the momentum fraction x 1 from the beam hadron and an anti-quark (quark) of the target nucleon with the momentum fraction x 2 annihilate via a virtual photon (contribution of the Z-boson exchange at the discussed energies is extremely small) into a charged-lepton pair:…”

“…The previous measurements of a nuclear dependence of the pion-induced Drell-Yan cross section have been performed in the NA3 [8] and NA10 [9] experiments. The ratio (3) measured by NA10 for tungsten and deuterium targets using a negative pion beam of 140 GeV/c and 286 GeV/c, is shown in the left and right panels of Fig 2 respectively.…”