Soft pions at high energy and its phenomenological implications
  The soft pion theorem in the inclusive reaction at high energy applied to the current induced reaction is explained briefly. A characteristic aspect of this theorem is the charge asymmetry produced by the pole terms in the soft pion limit. The pion charge asymmetry in the central region in the target-virtual-photon center of the mass (CM) frame of the semi-inclusive electroproduction and the contribution to the Gottfried sum are illustrated as examples. 
Susumu Koretune