The production of K+K- pairs in proton-proton collisions at 2.83 GeV

TL;DR

This study measures the production cross sections of K+K- pairs in proton-proton collisions at 2.83 GeV, distinguishing phi meson contributions and analyzing partial wave effects near threshold.

Contribution

It provides detailed differential and total cross sections for pp -> ppK+K- reactions and separates phi from non-phi production using model fits.

Findings

Higher partial waves dominate the phi production at 76 MeV excess energy.

Evidence of s-wave phi-p enhancement near threshold.

Non-phi production can be explained by two-body final state interactions.

Abstract

Differential and total cross sections for the pp -> ppK+K- reaction have been measured at a proton beam energy of 2.83 GeV using the COSY-ANKE magnetic spectrometer. Detailed model descriptions fitted to a variety of one-dimensional distributions permit the separation of the pp -> pp phi cross section from that of non-phi production. The differential spectra show that higher partial waves represent the majority of the pp -> pp phi total cross section at an excess energy of 76 MeV, whose energy dependence would then seem to require some s-wave phi-p enhancement near threshold. The non-phi data can be described in terms of the combined effects of two-body final state interactions using the same effective scattering parameters determined from lower energy data.