Further evidence for formation of a narrow baryon resonance with positive strangeness in K{sup +} collisions with Xe nuclei

Journal Article · Mon Jan 15 00:00:00 EST 2007 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S106377880701005X· OSTI ID:21075971

Barmin, V V; Asratyan, A E; Borisov, V S ^[1]; Curceanu, C ^[2]; Davidenko, G V; Guaraldo, C ^[2]; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tumanov, G K ^[1]

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1. Institute of Theoretical and Experimental Physics (Russian Federation)
2. Laboratori Nazionali di Frascati dell' INFN (Italy)

We have continued our investigation of the charge-exchange reaction K{sup +}Xe {sup {yields}} K{sup 0}pXe' in the bubble chamber DIANA. In agreement with our previous results based on part of the present statistics, formation of a narrow pK{sup 0} resonance with mass of 1537 {+-} 2 MeV/c{sup 2} is observed in the elementary transition K{sup +}n {sup {yields}} K{sup 0}p on a neutron bound in the xenon nucleus. The visible width of the peak is consistent with being entirely due to instrumental resolution and allows one to place an upper limit on its intrinsic width: {gamma} < 9 MeV/c{sup 2}. A more precise estimate of the resonance intrinsic width, {gamma} = 0.36 {+-} 0.11 MeV/c{sup 2}, is obtained from the ratio between the numbers of resonant and nonresonant charge-exchange events. The signal is observed in a restricted interval of incident K{sup +} momentum that is consistent with smearing of a narrow pK{sup 0} resonance by Fermi motion of the target neutron. The statistical significance of the signal is some 7.3, 5.3, and 4.3 standard deviations for the estimators S/{radical}B,S/{radical}(S+B) and S/{radical}(S+2B), respectively. This observation confirms and reinforces our earlier results, and offers strong evidence for formation of a pentaquark baryon with positive strangeness in the charge-exchange reaction K{sup +}n {sup {yields}} K{sup 0}p on a bound neutron.

• OSTI ID: 21075971
• Journal Information: Physics of Atomic Nuclei, Vol. 70, Issue 1; Other Information: DOI: 10.1134/S106377880701005X; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7788
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BUBBLE CHAMBERS
CHARGE EXCHANGE
CHARGE-EXCHANGE REACTIONS
COLLISIONS
KAONS NEUTRAL
KAONS PLUS
MASS
MEV RANGE
NEUTRONS
NUCLEI
PEAKS
RESOLUTION
RESONANCE
RESONANCE PARTICLES
STRANGENESS
XENON