Leading-twist pion and kaon distribution amplitudes in the   gauge-invariant nonlocal chiral quark model from the instanton vacuum
  We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon based on the gauge-invariant nonlocal chiral quark model from the instanton vacuum in the presence of external axial-vector currents. We find that the nonlocal contribution from the gauge invariance has much effects on the pion distribution amplitudes, while it changes mildly the kaon ones. We also study the Gegenbauer moments of the distribution amplitudes and compare them with the empirical analysis of the CLEO data. 
Seung-il Nam and Hyun-Chul Kim