Baryon -- anti-Baryon Photoproduction

TL;DR

This paper reports on the detailed study of baryon-antibaryon photoproduction off a proton target at Jefferson Lab, including the first observation of LambdaLambdabarrom thresholds up to 11.4 GeV, revealing multiple production mechanisms.

Contribution

It presents the first observation of LambdaLambdabarrom thresholds at Jefferson Lab and introduces a Monte Carlo simulation with four production mechanisms.

Findings

Observation of LambdaLambdabarrom thresholds to 11.4 GeV

Evidence of multiple production mechanisms in LambdaLambdabarormation

Comparison of simulation and data supports four proposed mechanisms

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.