Open strangeness threshold production at COSY-11

TL;DR

This paper reports on measurements of open strangeness production near threshold at COSY-11, focusing on hyperon and kaon pair production in proton-proton collisions, using missing mass techniques to identify unobserved particles.

Contribution

It extends measurements of hyperon production in different isospin channels and associated strangeness production, providing preliminary cross sections and analysis status.

Findings

Preliminary cross sections for pp->ppK+K- are presented.

Analysis of hyperon production channels is ongoing.

Experimental techniques involve reconstructing four-momentum and missing mass.

Abstract

The open strangeness production near threshold is investigated at the internal experiment COSY-11 in different reaction channels. Recently, the main focus has been to extend measurements of the hyperon production pp->pK+Lambda/Sigma0 in different isospin channels as well as the associated strangeness production in pp->ppK+K-. The experimental technique is based on the reconstruction of the four momentum for all positively charged ejectiles. Neutrons are detected in addition using a neutral particle detector. The unregistered hyperon or meson is identified by means of the missing mass technique. The present status of the analysis for both reaction channels is presented. In case of the reaction pp->ppK+K-, very preliminary cross sections are shown.