Hard exclusive baryon-antibaryon production in 2-γ collisions

We present a perturbative calculation of baryon pair production in two-photon collisions, $\gamma \gamma \to B \bar{B}$, in which baryons are treated as quark-diquark systems. Our approach accounts for constituent mass effects in a systematic way. Taking the diquark-model parameters from foregoing studies of other electron- and photon-induced baryonic reactions, our results agree well with the most recent large momentum-transfer data for the $p\bar{p}$, $\Lambda\bar{\Lambda}$, and $\Sigma^0\bar{\Sigma}^0$ channels.