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)].

Submitted to PRC

References in corpus (6)

• 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
• 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 (5)

• The reaction pi+ p --> K+ Sigma+ in a unitary coupled-channels model
• On the structure in the $\Lambda N$ cross section at the $\Sigma N$ threshold
• The measurement of the pp->K+ n Sigma+ reaction near threshold
• Coupled channels calculation of a pion-Lambda-nucleon quasibound state
• Meson Production at COSY-TOF and COSY-ANKE