Twist-3 contribution to the ${\gamma }^{\ast }\gamma \to \pi \pi$ amplitude in the Wandzura-Wilczek approximation

Abstract

We have calculated the Wandzura-Wilczek contribution to the twist-3 part of ${\gamma }^{\ast }\gamma \to 2\pi$ amplitude. It describes interaction of the longitudinally polarized virtual photon with the real one, and it is suppressed by 1/Q, where $Q^2$ is the virtuality of the ${\gamma }^{\ast }$, as compared to the twist-2 contribution. We have found that, in the Wandzura-Wilczek approximation, factorization applies to the twist-3 amplitude.

13 pages, 4 figures

References in corpus (10)

• Exclusive production of pion pairs in gamma^* gamma collisions at large Q^2
• On the gauge invariance of the DVCS amplitude
• Twist-three effects in two-photon processes
• DVCS amplitude in the parton model
• Wandzura-Wilczek approximation for the twist-3 DVCS amplitude
• Transversity Distribution Does Not Contribute to Hard Exclusive Electroproduction of Mesons
• On the Structure of the Virtual Compton Amplitude in the Generalized Bjorken Region: Integral Relations
• DVCS amplitude with kinematical twist-3 terms
• NLO corrections and contribution of a tensor gluon operator to the process ${\gamma }^{\ast }\gamma \to \pi \pi$
• On the twist-3 contribution to h_L in the instanton vacuum

Cited by in corpus (3)

• Wandzura-Wilczek approximation from generalized rotational invariance
• Duality between different mechanisms of QCD factorization in γ^*γcollisions
• Power corrections to the process ${\gamma }^{\ast }\gamma \to \pi \pi$ in the running coupling method