Speaker
Fulvio Piacenza
(Pavia University)
Description
In this talk, we discuss the transverse momentum distribution of Drell-Yan lepton pairs in fixed-target Drell-Yan experiments.
We show that fixed-order theory underestimates data at large qT, by an amount that cannot be explained by perturbative truncation errors nor PDF uncertainties. We consider a modification of the standard collinear formalism that includes the effect of intrinsic transverse momentum also at large qT. This is intended to parametrize possible higher-twist effects which are presently not under theoretical control.
