Charm production in ep interaction at HERA and evidence for a narrow anti-charmed baryon state at H1

TL;DR

This paper reports on charm production measurements at HERA, including evidence for a narrow anti-charmed baryon resonance at 3099 MeV observed by H1, suggesting potential discovery of an exotic baryon state.

Contribution

It presents new experimental evidence for an anti-charmed baryon state in ep interactions, highlighting a narrow resonance not seen in other analyses.

Findings

Observation of a narrow resonance at 3099 MeV in D*p invariant mass

Evidence supports the existence of an exotic anti-charmed baryon

Discrepancy between H1 and ZEUS results on this resonance

Abstract

Recent results on open charm production at HERA are presented. Charm quarks are identified via the reconstruction of D-mesons. The charm contribution to the proton structure function is shown. Evidence for an exotic anti-charmed baryon state observed by H1 is presented. The data show a narrow resonance in the D*p invariant mass combination at 3099+-3(stat)+-5(syst) MeV. The resonance is interpreted as an anti-charmed baryon with minimal constituent quark content uuddcbar together with its charge conjugate. Such a signal is not observed in a similar preliminary ZEUS analysis.