Semi-inclusive production of pions in DIS and $\bar{d}-\bar{u}$ asymmetry

Abstract

We discuss the role of some nonpartonic effects which lead to $N_p^{\ddot{I}{€}^{+}}\ne N_n^{\ddot{I}{€}^{+}}$ and $N_p^{\ddot{I}{€}^{-}}\ne N_n^{\ddot{I}{€}^{-}}$ and may therefore modify the conclusionon the $\bar{d}-\bar{u}$ asymmetry extracted from semi-inclusive production of pions in DIS. Quantitative estimations for resolved photon and exclusive $\ddot{I}{}^0$ are given as examples. The results are discussed in the context of recent HERMES data.

A talk given at the workshop "Meson2000", Cracow, Poland, 19-23 May 2000