Eur. Phys. J. C 25, 215-222 (2002)
The radiative return at small angles: virtual correctionsJ.H. Kühn1, 2 and G. Rodrigo1
1 Theory Division, CERN, 1211 Geneva 23, Switzerland
2 Institut für Theoretische Teilchenphysik, Universität Karlsruhe, 76128 Karlsruhe, Germany
(Received: 24 April 2002 / Published online: 12 July 2002 )
Virtual corrections for electron-positron annihilation into one real and one off-shell photon of invariant mass Q2 are evaluated. Special attention is paid to those configurations where the real photon is collinear with the beam direction. This calculation is an important ingredient of a Monte Carlo program, which simulates events with tagged photons from initial-state radiation, including NLO corrections.
© Società Italiana di Fisica, Springer-Verlag 2002