Braun, Vladimir M. and Ivanov, Dmitri Yu. and Lenz, Alexander and Peters, Andreas
Deep inelastic pion electroproduction at threshold.
Physical Review D 75 (1), 014021.
We consider the cross section of the deep inelastic pion electroproduction on a proton target at threshold for Q2 in the region 5–10 GeV2. The corresponding amplitudes are described in terms of two form factors which we calculate using light-cone sum rules to leading order in QCD and including higher twist corrections. Our results suggest a considerable change from a small Q2 region that can be treated in the soft-pion limit using current algebra. In particular, we obtain a π0 to π+ production ratio of order 1/3 and significant nucleon helicity-flip contributions.