$p\bar{p}\to {\Lambda }_c{\bar{\Lambda }}_c$ within the generalized parton picture - first results

Abstract

We study proton-antiproton annihilation into ${\Lambda }_c{\bar{\Lambda }}_c$ pairs within the generalized parton picture. Our starting point is the double handbag diagram which is shown to factorize into soft generalized parton distributions for the $p\to {\Lambda }_c$ (and $\bar{p}\to {\bar{\Lambda }}_c$) transition and a hard subprocess amplitude for $u\bar{u}\to c\bar{c}$. Thereby the mass of the charm quark is taken as the hard scale so that our results are not restricted to large scattering angles and/or incredibly large energies. Modelling the generalized parton distributions for the $p\to {\Lambda }_c$ transition by an overlap of simple quark-diquark light-cone wave functions we make first predictions for $p\to {\Lambda }_c$ transition form factors and unpolarized $p\bar{p}\to {\Lambda }_c{\bar{\Lambda }}_c$ cross sections. Our findings may become interesting in view of forthcoming experiments at FAIR in Darmstadt.

Comments: Talk given at Light Cone 2008: Relativistic Nuclear and Particle Physics, Mulhouse, France, 07-1 July 2008