Observation of a baryon resonance with positive strangeness in K+ collisions with Xe nuclei

Abstract

The status of our investigation of low-energy $K^{+}$Xe collisions in the Xenon bubble chamber DIANA is reported. In the charge-exchange reaction $K^{+}Xe\to K^{0}pX{e}^{\prime }$ the spectrum of $K^{0}p$ effective mass shows a resonant enhancement with $M=1539\pm 2$ MeV/c${}^2$ and $\hat{I}“\le 9MeV/c$^2$.Thestatisticalsignificanceoftheenhancementisnear$4.4σ$. The mass and width of the observed resonance are consistent with expectations for the lightest member of the anti-decuplet of exotic pentaquark baryons, as predicted in the framework of the chiral soliton model.

9 pages, 4 figures