New insights from the flavor dependence of quark transverse momentum distributions in the pion

We update our previous extraction of transverse momentum distributions of unpolarized quarks in the pion by implementing a more comprehensive description of theoretical uncertainties and, for the first time, by exploring possible differences among quark flavors. We extract such distributions from all available data for unpolarized pion-nucleus Drell-Yan processes, where the cross section is differential in the transverse momentum of the final lepton pair. The cross section involves transverse momentum distributions in the nucleon, that we consistently take from our previous studies. We find indications that inside the pion the valence quark may have wider tail at large transverse momenta with respect to the sea quark, a result that could not be exposed by the simple flavor-independent analysis. [The MAP (Multi-dimensional Analysis of Partonic distributions) Collaboration]