Jun 2 – 7, 2019
Carnegie Mellon University
America/New_York timezone

## Photoproduction of $\Xi$ Baryons at GlueX

Jun 7, 2019, 9:45 AM
30m
Rangos 2

### Speaker

Ashley Ernst (Florida State University)

### Description

Understanding the nature of the baryon spectrum will provide useful insight of quantum chromodynamics in the non-perturbative regime. Significant progress has been made in the $N^*$ regime, but little is known about doubly-strange hyperons. Most knowledge of the Cascade baryons stems from Kaon-nucleon experiments from the 1960s and 1970s or the more recent CLAS experiment at Jefferson Lab. This research studies these doubly-strange baryons via photoproduction using the GlueX experiment at Jefferson Lab. The Cascade octet ground state $\Xi^-$ can be studied by exclusive $t$-channel process in the reaction $\gamma p \to KY^* \to K^+(\Xi^-K^+)$ with the subsequent decay of the $\Xi^-$ into $\Lambda\pi^-$. The model suggests the intermediate hyperon $Y^*$ is broad and possibly consists of overlapping states. To better understand the production mechanism, the cross section for $\Xi^-$ is studied and extends the energies of the recently published cross section from CLAS g12. GlueX utilizes a linearly polarized photon beam which allows access to a quasi-two-body beam asymmetry ($\gamma p \to KY^*_{\Xi}$). The quasi-two-body beam asymmetry provides information about the $t$-channel exchange producing the intermediate hyperon. With GlueX Phase-I data taking concluded, preliminary results of the Cascade baryon spectrum are presented.

### Primary author

Ashley Ernst (Florida State University)