Hadron Spectroscopy in electrons-protons Collisions at HERA

TL;DR

This paper reviews recent HERA experiments searching for exotic baryons, including evidence for the strange pentaquark and anti-charmed baryon, along with negative search results.

Contribution

It provides a comprehensive overview of experimental searches for exotic baryons in electron-proton collisions at HERA, highlighting both positive evidence and null results.

Findings

Evidence for the strange pentaquark $ heta^+$ production.

Observation of a narrow anti-charmed baryon decaying to $D^{*-} p$.

Negative results in other pentaquark searches at HERA.

Abstract

Recent results from H1 and ZEUS on searches for exotic baryons in $ep$ collisions at HERA are reviewed. Evidence for the production of the strange pentaquark $\Theta^+$ and of a narrow anti-charmed baryon decaying to $D^{*-} p$ together with negative results of pentaquark searches at HERA are presented.