Probing moments of baryon-antibaryon generalized parton distributions at BELLE and FAIR

We analyze the time-like processes gamma gamma -> B (B) over bar and p (p) over bar -> gamma M at large Mandelstam variables within the handbag approach, for which the process amplitudes factorize in hard partonic subprocesses and annihilation form factors. The latter represent moments of baryon-antibaryon generalized parton distributions (GPDs). Symmetry relations restrict the number of independent annihilation form factors for the ground state baryons drastically. We determine these form factors from the present BELLE data on gamma gamma -> B (B) over bar with the help of simplifying assumptions. The knowledge of these form factors allow for predictions of p (p) over bar -> gamma M for various mesons which may be probed at FAIR.