Professor Brian Foster OBE, FRS

Abstract:

We report on the results of a partial-wave analysis of the 3π system produced by baryon exchange in the reaction K-p→Σ-π+π+π- at 4.2 GeV/c. We confirm the existence of an enhancement in the 1+S(ρ{variant}π) wave as previously established from a Dalitz plot analysis of the same data. The phase variation of this wave is found to be consistent with that expected for a resonance and thus the enhancement is identified with A1 production. No clear signal for this state is found in either the reaction K-p→Σ+π+π+π-π- or K-p→Λπ+π-π0. We also find production via baryon exchange of the A2 in all three reactions and the ω and ω* (1975) in the third reaction. © 1981.

Abstract:

The reactions K-p → Ξ 0 -(1320)K 0 +, Ξ-(1320)K+(890), Ξ 0 -(1530) K 0 - and Ξ 0 -(1530)K 0 +(890) are studied at 4.2 GeV/c incident momentum. The data come from a high-statistics bubble chamber experiment with a sensitivity of ∼ 133 events/μb. Total anddifferential cross sections are presented. The results are compared to the SU(3)-related processes K+p → pK+ and K+p → pK+(890) in the backward hemisphere. In the forward hemisphere "forbidden" peaks are observed and current ideas about them are discussed. © 1981.