Speaker
Description
We present a calculation of the connected-diagram contributions to the
first three non-trivial Mellin moments for the pion and kaon extracted
directly in lattice QCD using local operators with up to 3 covariant
derivatives. We reconstruct the $x$-dependence of the pion and kaon
PDFs via fits to our results. We find that the reconstruction is
feasible and that our lattice data favor a large $x$-dependence that
falls as $(1-x)^2$ for both the pion and kaon PDFs. We integrate the
reconstructed PDFs to extract the higher moments with $4\leq n\leq 6$.
Finally, we compare the pion and kaon PDFs, as well as the ratios of
their moments, to address the effect of SU(3) flavor symmetry
breaking. We use one ensemble of gauge configurations with two
degenerate light, a strange and a charm quark ($N_f=2+1+1$) of
maximally twisted mass fermions with clover improvement. The ensemble
reproduces a pion mass $\sim260$ MeV, and a kaon mass $\sim530$ MeV.