Search for a Narrow Baryonic Resonance Decaying to $K^0_s p$ or $K^0_s \bar{p}$ in Deep Inelastic Scattering at HERA

TL;DR

This study searches for a hypothesized narrow baryonic resonance decaying into specific strange particles in deep inelastic scattering at HERA, but finds no significant evidence for its existence within the examined mass range.

Contribution

It provides the first comprehensive search for the strange pentaquark hplns in deep inelastic ep scattering at HERA and sets upper limits on its production.

Findings

No significant peak observed in the invariant mass distributions.

Mass-dependent upper limits on production cross-section times branching ratio.

Constraints on the existence of the strange pentaquark hplns.

Abstract

A search for a narrow baryonic resonance decaying to $K^0_s p$ or $K^0_s \bar p$ is carried out in deep inelastic ep scattering with the H1 detector at HERA. Such a resonance could be a strange pentaquark \thplns, evidence for which has been reported by several experiments. The $K^0_s p$ and $K^0_s \bar p$ invariant mass distributions presented here do not show any significant peak in the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on $\sigma(ep \to e \thplf X)\times BR(\thplf \to K^0 p)$ are obtained at the 95% confidence level.