6533b836fe1ef96bd12a1a21

RESEARCH PRODUCT

Enhancement effects in exclusive pi pi production in gamma* gamma scattering

subject

description

The exclusive pi pi and rho pi production in hard gamma*gamma scattering in the forward kinematical region where the virtual photon is highly off-shell is studied using the gamma -> pi(-) Transition Distribution Amplitudes obtained in realistic models for the pion. For rho pi production we confirm the previous estimates before QCD evolution. Nevertheless. once evolution is taken into account this cross section grows one order of magnitude. In the case of pi pi production we have evaluated the cross section including the pion pole contribution. We observe that this contribution is responsible for an enhancement of two orders of magnitude with respect to the cross section evaluated without the pion pole term.