Search for an exotic S=-2, Q=-2 baryon resonance in proton-proton interactions at $\sqrt{s_{NN}}$ = 17.3~GeV

Pentaquark states have been extensively investigated theoretically in the context of the constituent quark model. In this paper experimental searches in the $\Xi^-$$\pi^-$, $\Xi^-$$\pi^+$, $\bar{\Xi}^+$$\pi^-$ and $\bar{\Xi}^+$$\pi^+$ invariant mass spectra in proton-proton interactions at $\sqrt{s}$=17.3~GeV are presented. Previous possible evidence from the NA49 collaboration of the existence of a narrow $\Xi^-$$\pi^-$ baryon resonance in p+p interactions is not confirmed with almost 10 times greater event statistics. The search was performed using the NA61/SHINE detector which reuses the main components of the NA49 apparatus. No signal was observed with either the selection cuts of NA49 or a newly optimised set.