The energy dependence of the pp->K+ n Sigma+ reaction close to threshold

Abstract

The production of the Sigma+ hyperon through the pp->K+nSigma+ reaction has been investigated at four energies close to threshold, 1.826, 1.920, 1.958, and 2.020 GeV. At low energies, correlated K+pi+ pairs can only originate from Sigma+ production so that their measurement allows the total cross section for the reaction to be determined. The results obtained are completely consistent with the values extracted from the study of the K+-proton correlation spectra obtained in the same experiment. These spectra, as well as the inclusive K+ momentum distributions, also provide conservative upper limits on the Sigma+ production rates. The measurements show a Sigma+ production cross section that varies roughly like phase space and, in particular, none of the three experimental approaches used supports the anomalously high near-threshold pp->K+ nSigma+ total cross section previously reported [T. Rozek et al., Phys. Lett. B 643, 251 (2006)].

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References in corpus (12)

• Nucleon-nucleon elastic scattering to 3 GeV
• Evidence for a narrow resonance at 1530 MeV/c2 in the K0 p - system of the reaction pp --> Sigma+ K0 p from the COSY-TOF experiment
• Total Cross Section of the Reaction pp \to pK^+ΛClose to Threshold
• Comparison of Lambda and Sigma(0) Threshold Production in Proton-Proton Collisions
• Energy dependence of the Lambda/Sigma0 production cross section ratio in proton proton interactions
• The role of ${\Delta }^{++\ast }(1620)$ resonances in $pp\to n{K}^{+}{\Sigma }^{+}$ reaction and its important implications
• Threshold hyperon production in proton-proton collisions at COSY-11
• High resolution study of the Lambda p final state interaction in the reaction p + p -> K+ + (Lambda p)
• Improved study of a possible Theta+ production in the pp -> p K0 sigma+ reaction with the COSY-TOF spectrometer
• The pp->K+ n Sigma+ reaction near threshold
• The pp -> K^+Sigma^+n cross section from missing mass spectra
• Strangeness Production Process $pp\to n{K}^{+}{\Sigma }^{+}$ within Resonance Model

Cited by in corpus (18)

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• The reaction pi+ p --> K+ Sigma+ in a unitary coupled-channels model
• Baryonic resonances close to the Kbar-N threshold: the case of Sigma(1385)^+ in pp collisions
• A Three-Flavor Chiral Effective Model with Four Baryonic Multiplets within the Mirror Assignment
• Strangeness production via resonances in heavy-ion collisions at SIS energies
• The pK0Σ+ final state in proton-proton collisions
• On the structure in the $\Lambda N$ cross section at the $\Sigma N$ threshold
• Medium effects in $\Lambda K^{+}$ pair production by 2.83 GeV protons on nuclei
• The measurement of the pp->K+ n Sigma+ reaction near threshold
• Upper limits for a narrow resonance in the reaction p + p -> K^+ + (Lambda p)
• Coupled channels calculation of a pion-Lambda-nucleon quasibound state
• Complete Strangeness Measurements in Heavy-Ion Collisions
• Reexamination of the role of the ${\Delta }^{\ast }$ resonances in the $pp\to n{K}^{+}{\Sigma }^{+}$ reaction
• Role of scalar dibaryon and $f_0(500)$ in the isovector channel of low-energy neutron-proton scattering
• Comparison of inclusive K+ production in proton-proton and proton-neutron collisions
• Strangeness Production in Hadron Reactions
• Meson Production at COSY-TOF and COSY-ANKE
• Three-flavor chiral effective model with four baryonic multiplets within the mirror assignment