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

The data on the charge-exchange reaction K+Xe → K0pXe′, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK0 resonance with mass near 1538 MeV is confirmed. The statistical significance of the signal reaches some 8 (6) standard deviations when estimated as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {S \mathord{\left/ {\vphantom {S {\sqrt B \left( {{S \mathord{\left/ {\vphantom {S {\sqrt {B + S} }}} \right. \kern-\nulldelimiterspace} {\sqrt {B + S} }}} \right)}}} \right. \kern-\nulldelimiterspace} {\sqrt B \left( {{S \mathord{\left/ {\vphantom {S {\sqrt {B + S} }}} \right. \kern-\nulldelimiterspace} {\sqrt {B + S} }}} \right)}} $$\end{document}. The mass and intrinsic width of the Θ+ baryon are measured as m = 1538 ± 2 MeV and Γ = 0.39 ± 0.10 MeV.