Eur. Phys. J. A (2012) 48: 23
https://doi.org/10.1140/epja/i2012-12023-8

Regular Article - Experimental Physics

The pK⁰Σ⁺ final state in proton-proton collisions

¹ Institut für Kern- und Teilchenphysik, Technische Universität Dresden, D-01062, Dresden, Germany
² Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058, Erlangen, Germany
³ Institut für Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
⁴ Physikalisches Institut, Universität Tübingen, D-72076, Tübingen, Germany
⁵ Institut für Strahlenphysik, Helmholtzzentrum Dresden-Rossendorf, Postfach 51 01 19, D-01314, Dresden, Germany
⁶ Soltan Institute for Nuclear Studies, 05-400, Swierk/Otwock, Poland
⁷ INFN Torino, 10125, Torino, Italy
⁸ Helmholtz Institut für Strahlen- und Kernphysik, Rheinische Friedrich-Wilhelm-Universität Bonn, D-53115, Bonn, Germany
⁹ Institut für Experimentalphysik, Ruhr-Universität Bochum, D-44780, Bochum, Germany

^* e-mail: m.schulte-wissermann@physik.tu-dresden.de

Received: 20 October 2011
Revised: 16 January 2012
Accepted: 1 February 2012
Published online: 28 February 2012

Abstract

This paper reports results from a study of the reaction pp → pK⁰Σ⁺ at beam momenta of p _beam = 2950, 3059, and 3200 MeV/c (excess energies of ε = 126, 161, and 206 MeV. Total cross-sections were determined for all energies; a set of differential cross-sections (Dalitz plots; invariant-mass spectra of all two-body subsystems; angular distributions of all final-state particles; distributions in helicity and Jackson frames) are presented for ε = 161 MeV. The total cross-sections are proportional to the volume of available three-body phase space indicating that the transition matrix element does not change significantly in this range of excess energies. It is concluded from the differential data that the reaction proceeds dominantly via the N(1710)P ₁₁- and/or N(1720)P ₁₃-resonance(s); N(1650)S ₁₁ and Δ(1600)P ₃₃ could also contribute.