J/ψ plus prompt-photon associated production in two-photon collisions at next-to-leading order
Michael Klasen, Bernd A. Kniehl, Luminita N. Mihaila, Matthias Steinhauser · Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · 2005
We calculate the cross section of $J/\ensuremath{\psi}$ plus prompt-photon inclusive production in $\ensuremath{\gamma}\ensuremath{\gamma}$ collisions at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) focusing on direct photoproduction. Apart from direct $J/\ensuremath{\psi}$ production, we also include the feed-down from directly produced ${\ensuremath{\chi}}_{cJ}$ and ${\ensuremath{\psi}}^{\ensuremath{'}}$ mesons. We discuss the analytical calculation, in particular the treatment of the various types of singularities and the NRQCD operator renormalization, in some detail. We present theoretical predictions for the future ${e}^{+}{e}^{\ensuremath{-}}$ linear collider TESLA, taking into account both brems- and beamstrahlung.