B_c meson production in \gamma\gamma collisions and charm content of the photon

Abstract

Based on photon structure function formalism we have calculated $B_c(B_c^{\ast })$ meson production cross section in $\gamma \gamma$ collisions via partonic subprocess $c\gamma \to B_c(B_c^{\ast })b$. It was shown that this approach gives the same results for $B_c^{\ast }(B_c)$ meson cross sections as the direct leading order QCD calculation of the subprocess $\gamma \gamma \to B_c(B_c^{\ast })b\bar{c}$ at small energy. Howere, opposite to the direct QCD calculation we have obtained the increase of the $B_c(B_c^{\ast })$ meson cross section at large energies. We have found also additional contribution to the $B_c$ meson production via the nonperturbative fluctuations $\gamma \leftrightarrow J/\psi$.

Comments: LaTeX, 7 pages and 6 figures available upon request