Baryon -- anti-Baryon Photoproduction

Abstract

Baryon - anti-baryon photoproduction off a proton target is being studied in detail at Jefferson Lab with the GlueX Experiment. We observe $p\bar{p}$ and, for the first time, $\Lambda\bar{\Lambda}$ photoproduction (with $\Lambda \rightarrow \pi^- p$, $\bar{\Lambda} \rightarrow \pi^+ \bar{p}$) from thresholds up to $E_{\gamma} = 11.4$ GeV. Preliminary spectra from data accumulated during the GlueX Phase-I period are shown. Angular distributions of the photoproduced hyperons indicate more than one production mechanism in the reaction channel $\gamma p \rightarrow \Lambda\bar{\Lambda}p$. A Monte Carlo simulation with four mechanisms, tested through comparison between simulation and experimental data, is presented.