Study of the hadronic production of kaon pairs below the threshold for the phi meson

TL;DR

This study investigates near-threshold production of K+K- pairs in proton-proton collisions, revealing significant enhancements near the threshold likely due to K-p interactions, with stronger proton-K- than proton-K+ interactions observed.

Contribution

First detailed analysis of K+K- production below phi meson threshold, highlighting the influence of K-p interactions and providing new qualitative insights into event distributions.

Findings

Significant enhancement near the production threshold.

Strong proton-K- interaction compared to proton-K+.

Event density increases where K+K- interactions are expected.

Abstract

The near threshold production of K+K- pairs in proton-proton collisions has been investigated at the cooler synchrotron COSY below and above the threshold for the $\phi$ meson using the COSY-11 and ANKE facilities, respectively. The excitation function determined for the pp-->ppK+K- reaction revealed a statistically significant enhancement close to the threshold which may plausibly be assigned to the influence of the K-p interaction. In addition, observed consistently by both groups, a strong enhancement at low values of the ratio of the K-p to K+p invariant mass distributions shows that the proton interacts much stronger with K- than with K+. In this report we focus on the measurements performed by the COSY-11 collaboration. We explain the experimental method used and present main results of completed analyses as well as a new qualitative elaboration of the ppK+K- events population on the Goldhaber plot. We conclude with the observation that event densities increase at the region where the influence from the K+K- interaction is expected.