HYP2018: 13th International Conference on Hypernuclear and Strange Particle Physics

Photoproduction of Lambda-AntiLambda Pairs at GlueX.

Not scheduled

15m

2nd Floor

Abstract Submission

Speaker

Dr Reinhard Schumacher (Carnegie Mellon University)

Description

The mechanism of baryon-antibaryon photoproduction has not been extensively studied. Little is known about the dominant exchanges in the $t$-channel or the nature of baryon-like exchanges in the $u$- channel. At GlueX, we are studying the reactions $\gamma p\to \bar{\mathcal{B}}\mathcal{B}$$p$, where $\bar{\mathcal{B}}\mathcal{B}$ includes $\bar{\mathrm{\Lambda }}\mathrm{\Lambda }$ and $\bar{p}p$. Kinematic fitting is used for the $\bar{\mathrm{\Lambda }}\mathrm{\Lambda }$ channel to extract the 5-body final states with $\mathrm{\Lambda }\to {\pi }^{-}p$ and $\bar{\mathrm{\Lambda }}\to {\pi }^{+}\bar{p}$ . Data have been obtained from the respective reaction thresholds up to a beam energy of about 11 GeV. Photons in the energy range between 8.4 and 9 GeV were linearly polarized, allowing examination of observables like the beam spin asymmetry. Preliminary spectra from data obtained in Spring 2016 and Spring 2017 will be shown for the angular correlations among the produced particles. Our goal is to use spin correlations between the $\mathrm{\Lambda }$ hyperons to determine the angular momentum structure of the strangeness production mechanism.