Photoproduction of Exotic Baryon Resonances

TL;DR

This paper proposes testing the exotic baryon resonances observed by LHCb through photoproduction experiments at JLAB, aiming to confirm their resonant nature and explore their molecular structure.

Contribution

It introduces a novel experimental approach to verify the nature of exotic baryon resonances and estimates their production cross sections using vector dominance.

Findings

Photoproduction cross sections are within experimental reach at JLAB.

The heavier state may be a $ ext{Σ}_c$-$ar{D}^*$ molecule.

Predictions extend to analogous $ ext{Υ} p$ resonances.

Abstract

We point out that the new exotic resonances recently reported by LHCb in the $J/\psi p$ channel are excellent candidates for photoproduction off a proton target. This test is crucial to confirming the resonant nature of such states, as opposed to their being kinematical effects. We specialize to an interpretation of the heavier narrow state as a molecule composed of $\Sigma_c$ and $\bar D^*$, and estimate its production cross section using vector dominance. The relevant photon energies and fluxes are well within the capabilities of the GlueX and CLAS12 detectors at Thomas Jefferson National Accelerator Facility (JLAB). A corresponding calculation is also performed for photoproduction of an analogous resonance which is predicted to exist in the $\Upsilon p$ channel.