Hard exclusive electroproduction of pions

L. Mankiewicz; G. Piller; A. Radyushkin

doi:doi:10.1007/s100529900045

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

2022 Impact factor 4.4

Particles and Fields

Eur. Phys. J. C 10, 307-312
DOI 10.1007/s100529900045

Hard exclusive electroproduction of pionsThis work has been supported in part by BMBF

L. Mankiewicz^1,2 - G. Piller¹ - A. Radyushkin^3,4,5

¹ Physik Department, Technische Universität München, D-85747 Garching, Germany
² Copernicus Astronomical Center, ul. Bartycka 18, PL-00-716 Warsaw, Poland
³ Physics Department, Old Dominion University, Norfolk, VA 23529, USA
⁴ Jefferson Lab, Newport News, VA 23606, USA
⁵ Laboratory of Theoretical Physics, JINR, Dubna, Russian Federation

Received: 4 January 1999 / Published online: 15 July 1999

Abstract
We investigate the exclusive electroproduction of $\pi^+$ mesons from nucleons. To leading-twist, leading-order $\alpha_s$ accuracy, the corresponding production amplitude can be decomposed into pseudovector and pseudoscalar parts. Both can be expressed in terms of quark double distribution functions of the nucleon. While the pseudovector contribution is connected to ordinary polarized quark distributions, the pseudoscalar part can be related to one-pion t-channel exchange. We observe that the pseudovector part of the production amplitude is important at $x_{\rm Bj} < 0.1$ . On the other hand, for $0.1< x_{\rm Bj} < 0.4$ , contributions from one-pion exchange dominate.