Professor Brian Foster OBE, FRS

Abstract:

Forty Ω^- events have been observed in a large (133 events/βb) experiment at 4.2 GeV/c incident K^- momentum. Thirty nine of the events come from the three-body reaction K^-p→Ω^-K⁺K⁰. The Ω^- is mainly produced in the forward hemisphere (direction of the incident K^-). The lifetime is measured to be τ = (0.75 +0.14-0.11 × 10^-10 sec substantially less than the Particle Data Group value of (1.3 -0.3^+0.2) × 10^-10 sec. The mass is determined to be 1671.7 ± 0.6 MeV, in good agreement with other determinations. The decay asymmetry parameter α (for the decay mode Ω^- → ΛK^-) is found to be -0.2 ± 0.4. © 1978.

Abstract:

Evidence is presented for an I = 1 enhancement observed in the reactions K-p→Λ(Σ)K01K ±π∓ at 4.2 GeV c inciden momentum. The mass and width of the proposed new Y* are, respectively, (1553 ± 7) MeV) and (80 ± 30) MeV. A decay branching ratio Σπ (Σπ + Λπ) = (35 ± 12)% is also obtained. © 1978.

Abstract:

The backward production of the B(1235) meson is studied in the reaction K-p→Σ-π+ω. This reaction is observed in the final state Σ-π+π+π-π 0. A π+ω mass enhancement is visible in the region of the B meson for events with small |u|K- →Σ-) squared four-momentum transfer. The properties of the enhancement agree with those of the B meson. The cross section for K-p→Σ-B+ at 4.15 GeV c incident K- momentum is (3.2 ± 0.5) μb. The backward production of the B meson is compared with similar baryon exchange productions of the A1 and C(Q1) axial vector mesons observed in the same experiment. © 1978.

Abstract:

Using a spin test proposed recently by Minnaert, we determine the spin of the Ξ* (1820) resonance to be 3 2. © 1978.

Abstract:

A 2.5 standard deviation signal is observed for the decay K^*-(1420) → K^*-(892)π⁺π^-. From this signal a partial width of 13.0 ± 5.0 MeV for the decay mode K^*(1420)→K^*(892)ππ is deduced under the assumption that the ππ system is in an I = 1 state. For the rare decay mode K^*(892)→Kππ no signal is observed. The following upper limits can be given for the decay widths: ΓK^*-(892) → K^-π⁺π^- < 40 keV, ΓK^*-(892) → K⁰π^-π⁰ < 35 keV, ΓK^*0(892) → K⁰π⁺π^- < 35 keV. © 1978.