A Study of 2-pion production in 10 GeV/c K+ Meson interactions in hydrogen

Thesis

This thesis contains an analysis of the two reactions,

• K⁺p → K⁺π⁺π⁻p; and
• K⁺p → K⁰π⁺π⁰p

at an incident K⁺ momentum of 10 GeV/c, which were observed in the C.E.R.N. 2m Hydrogen Bubble Chamber.

The resonances Δ⁺⁺(1236), K^*0(890) and K^*0(1420) are strongly produced in these data. To investigate the possible existence of a scalar K_N(1100) resonance, calculations were performed on the K^*0 – Δ⁺⁺(1236), quasi two-body state, using modified one-pion-exchange formulae. The presence of a large I = ¹⁄₂, s-wave phase shift in the region of 1.1 GeV/c² is indicated but is not required to be resonant.

The enhancement between 1.2 and 1.45 GeV/c² in Kππ mass, present in these data, is determined to have a dominant spin-parity of 1⁺ throughout. Evidence for two 1⁺ resonances in this mass region is obtained from an analysis of the variations, with mass, of the decay properties of this system.

A low mass pππ enhancement is present in the data from K⁺π⁺π⁻p final state, only. A study of the production and decay characteristics of this system would seem to suggest that it is composed of the I = ¹⁄₂ resonances in the spin-parity series ¹⁄₂⁺, ³⁄₂⁻, ⁵⁄₂⁺, known from elastic π-p phase shift analyses.

Authors: Alper, B; Alper, B.

• Publication date: 1970
• DOI: 10.5287/ora-bdjonxmbx
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English