Self-consistent covariant description of twist-3 distribution amplitude   of a pseudoscalar meson in the light-front quark model
  We discuss the light-front zero-mode issue in the light-front quark model prediction of the twist-3 distribution amplitude of a pseudoscalar meson from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. 
Ho-Meoyng Choi (Kyungpook National Univ.), Chueng-Ryong Ji (North   Carolina State Univ.)
hep-ph