Search for a narrow charmed baryonic state decaying to D^*+/- p^-/+ in ep collisions at HERA

TL;DR

This study searched for a narrow charmed baryonic state decaying to D^*+/- p^-/+ in ep collisions at HERA but found no evidence of such a resonance, challenging previous claims of a charmed pentaquark.

Contribution

The paper presents a comprehensive resonance search in the D^*+/- p^-/+ spectrum using ZEUS data, providing the first extensive negative result in this channel.

Findings

No resonance observed in the D^*+/- p^-/+ mass spectrum.

Results do not support the existence of the charmed pentaquark Theta^0_c.

Over 60,000 D^*+/- mesons reconstructed without resonance signals.

Abstract

A resonance search has been made in the D^*+/- p^-/+ invariant-mass spectrum with the ZEUS detector at HERA using an integrated luminosity of 126 pb^-1. The decay channels D^*+ -> D^0 pi^+_s -> (K^- pi^+) pi^+_s and D^*+ -> D^0 pi^+_s -> (K^- pi^+ pi^+ pi^-) pi^+_s (and the corresponding antiparticle decays) were used to identify D^*+/- mesons. No resonance structure was observed in the D^*+/- p^-/+ mass spectrum from more than 60000 reconstructed D^*+/- mesons. The results are not compatible with a report of the H1 Collaboration of a charmed pentaquark, Theta^0_c.