Kaon pair production in proton-proton collisions at COSY-ANKE

¹ Department of Physics and Triangle Universities Nuclear Laboratory, Duke University, Durham, NC 27708, USA
² Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany

^a e-mail: qy4@phy.duke.edu

Abstract

The near-threshold production of kaon-pairs has been investigated in proton-proton collisions at Cooler Synchrotron (COSY)at Forschungszentrum Jülich. In the pp → ppK⁺K⁻ reaction, the invariant mass distributions of K⁻p, K⁻pp, and K⁺K⁻ indicate the presence of both K⁻p and K⁺K⁻ final state interactions. Total cross sections for pp → ppϕ reaction have been determined at excess energies ε of 18.5, 34.5, and 76 MeV. The differential spectra at an excess energy of 18.5 MeV exhibit a clear s-wave dominance, while the high statics data at an excess energy of 76 MeV shows that higher partial waves represent the majority of the pp → ppϕ total cross section, whose energy dependence would then seem to require some s-wave ϕp enhancement near threshold.