Pseudoscalar mesons parton distribution amplitudes

Abstract

We compute all kaon and pion parton distribution amplitudes (PDAs) to twist-three and find that all of the pion’s distributions are symmetric and all of the kaon’s distributions are skewed in favour of the heavier s-quark, which are clear signals of dynamical chiral symmetry breaking (DCSB). And we can also notice that only the pseudotensor PDA can reasonably be approximated by its conformal limit. At any realistic energy scale, the pseudovector and pseudoscalar PDAs differ markedly from the corresponding functions in QCD’s conformal limit. We can use these PDAs as the inputs to study hard exclusive processes and get trustable results.