Hard exclusive electroproduction of a pion in the backward region

Abstract

We study the scaling regime of pion electroproduction in the backward region, eN->e'N'pi. We compute the leading-twist amplitude in the kinematical region, where it factorises into a short-distance matrix element and long-distance dominated nucleon Distribution Amplitudes and nucleon to pion Transition Distribution Amplitudes. Using the chiral limit of the latter, we obtain a first estimate of the cross section, which may be experimentally studied at JLab or Hermes.

Comments: 8 pages, 17 figures, RevTeX; v3: update according to an erratum to be published by Phys Rev D : equations (19), (28) and (29) are modified and Fig. 3 corrected accordingly; Conclusions unchanged