Observation of narrow baryon resonance decaying into $p{K}_s^0$ in pA-interactions at $70GeV/c$ with SVD-2 setup

Abstract

SVD-2 experiment data have been analyzed to search for an exotic baryon state, the ${\Theta }^{+}$-baryon, in a $p{K}_s^0$ decay mode at $70GeV/c$ on IHEP accelerator. The reaction $pA\to p{K}_s^0+X$ with a limited multiplicity was used in the analysis. The $p{K}_s^0$ invariant mass spectrum shows a resonant structure with $M=1526\pm 3(stat.)\pm 3(syst.)MeV/c^2$ and $\Gamma <24MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6\sigma$. The mass and width of the resonance is compatible with the recently reported ${\Theta }^{+}$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\bar{s}$) baryon state. The total cross section for ${\Theta }^{+}$ production in pN-interactions for $X_F\ge 0$ was estimated to be $(30÷120)\mu b$ and no essential deviation from A-dependence for inelastic events $(\sim A^{0.7})$ was found.

8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos corrected

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Cited by in corpus (23)

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• Evidence of the Θ^+ in the γd \to K^+K^-pn reaction
• Chiral-Soliton Predictions for Exotic Baryons
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• Evidence for the B0->ppbarK*0 and B+->eta_cK*+ decays and Study of the Decay Dynamics of B Meson Decays into ppbarh Final States
• Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS
• Improved study of a possible Theta+ production in the pp -> p K0 sigma+ reaction with the COSY-TOF spectrometer
• Experimental Review on Pentaquarks
• Search for Theta+ via K+p -> pi+X reaction with a 1.2 GeV/c K+ beam
• Present status on experimental search for pentaquarks
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• A possible explanation why the Theta+ is seen in some experiments and not in others
• Search for a pentaquark decaying to p K_S^0
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• Theta+ formation in inclusive gamma D -> pK- X
• Properties of the Lambda(1520) Resonance from High-Precision Electroproduction Data
• Absence of evidence for pentaquarks on the lattice
• Regge Trajectories of Exotic Hadrons in the Flux Tube Model
• Search for Exotic S=-2 Baryons in proton-antiproton Collisions at sqrt(s) = 1.96 TeV
• On influence of experimental resolution on the statistical significance of a signal: implication for pentaquark searches
• Positive parity pentaquark towers in large Nc QCD
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• Kinematic selection criteria in a new resonance searches: Application to pentaquark states