Measurement of the pn -> dK^+K^- total cross section close to threshold

TL;DR

This study measures the total cross section of the pn -> dK^+K^- reaction near threshold energies, revealing the influence of final state interactions and comparing results with similar proton-proton reactions.

Contribution

First measurement of the pn -> dK^+K^- total cross section near threshold, highlighting final state interactions and comparing with related reactions.

Findings

Evidence of K^-d and KKbar final state interactions.

Total cross sections are similar across pn and pp reactions.

Data extends understanding of near-threshold meson production.

Abstract

Measurements of the pn -> p_spec dK^+K^- reaction, where p_spec is a spectator proton, have been undertaken at the Cooler Synchrotron COSY-Juelich by detecting a fast deuteron in coincidence with a K^+K^- pair in the ANKE facility. Although the proton beam energy was fixed, the moving target neutron allowed values of the non-resonant quasi-free pn -> dK^+K^- total cross section to be deduced up to an excess energy epsilon ~ 100 MeV. Evidence is found for the effects of K^-d and KKbar final state interactions. The comparison of these data with those of pp -> ppK^+K^- and pp -> dK^+Kbar shows that all the total cross sections are very similar in magnitude.