Recent Progress on Pion Valence-Quark and Gluon Distributions from Lattice QCD

We present recent progress on lattice-QCD calculations of the pion valence-quark and gluon PDFs. All these calculations are done on ensembles with $N_f=2+1+1$ highly improved staggered quarks (HISQ), generated by the MILC Collaboration. The valence-quark PDF of the pion is calculated at lattice spacing 0.09~fm with physical pion masses using LaMET method with perturbative matching at next-to-next-to-leading order. We study and compare the effects of systematic errors by applying hybrid renormalization schemes with leading-renormalon and renormalization-group resummation improvements. On the gluon PDFs, we present the first pion calculation at the continuum-physical limit with 3 pion masses and 3 lattice spacings, and update MSULat's previous pion gluon PDFs.