Global QCD Analysis of Pion Parton Distributions Using Threshold Resummation*

We perform the first global QCD analysis on pion valence quark, sea quark, and gluon distributions including threshold resummation on Drell-Yan cross sections within a Bayesian Monte Carlo framework. Various methods of threshold resummation stemming from treatment of the rapidity distribution are applied systematically on the pion-nucleus Drell-Yan observables. We present the results of the large momentum fraction behavior of the valence quark distribution, which differs significantly depending on the method of resummation. In contrast, the momentum fractions of the various distributions are equal within uncertainties regardless of the resummation method.