Eur. Phys. J. A (2007) 32: 273-291
https://doi.org/10.1140/epja/i2007-10374-9

Regular Article - Hadron Physics

Exclusive electroproduction of pion pairs

¹ Institut für Theoretische Physik, Universität Regensburg, 93040, Regensburg, Germany
² Deutsches Elektronen-Synchrotron DESY, 22603, Hamburg, Germany
³ Sobolev Institute of Mathematics, 630090, Novosibirsk, Russia

Received: 24 April 2007
Accepted: 12 May 2007
Published online: 8 June 2007

Abstract

We investigate electroproduction of pion pairs on the nucleon in the framework of QCD factorization for hard exclusive processes. We extend previous analyses by taking the hard-scattering coefficients at next-to-leading order in α_s . The dynamics of the produced pion pair is described by two-pion distribution amplitudes, for which we perform a detailed theoretical and phenomenological analysis. In particular, we obtain constraints on these quantities by comparing our results with measurements of angular observables that are sensitive to the interference between two-pion production in the isoscalar and isovector channels.