The production and decay of sigma hyperons by kaons at rest

Abstract

A sample of 22354 K(^-)-meson interactions at rest leading to the channels K(^-)P→Σ(^±)π(^±) has been obtained from an exposure to the British National Hydrogen Bubble Chamber containing a track sensitive target. The data have been used to determine ┌, which is the ratio of the production of Σ(^-) hyperons to the production of Σ(^+)- hyperons. The quantity B, which is the branching fraction of Σ(^+)- hyperons into positive pions has been determined simultaneously. The value of B (=0,487±-0.008) is in close agreement with the known world value which gives confidence in the sample and in the method that have been used to determine B and ┌. The value of T┌ (=2,35±0.07) resolve the existing discrepancy between the known measured values. This thesis contains a description of the importance of ┌, an account of the experiment including a detailed consideration of how the ratios were determined.