Future Colliders

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.

Abstract:

A (Kππ)⁺ mass enhancement is observed in the reactions K^-p → Ξ -K^o+π⁺π^o- when events with a small (K^- → Ξ^-) four momentum transfer squared are selected. The signal is also visible in the reaction K^-p → Ξ^-π⁺+ neutrals. The enhancement, centered at 1.28 GeV, is seen to decay preferentially into Kρ{variant} with spin-parity J^P = 1⁺. The cross section for K^-p→ Ξ^-C⁺(1.28) with C⁺ → Kρ{variant} at 4.15 GeV/c incident K^- momentum is (6.2 ± 0.6) μb. © 1978.

Abstract:

The vector meson production, hypercharge exchange reactions K^-p → (φ, ω, ρ{variant}) Λ and (φ, ρ{variant}) Σ⁰ are studied at 4.2 GeV/c incident momentum. The data come from a high statistics bubble chamber experiment with a sensitivity of ∼ 120 events/μb. Total and differential cross sections are presented. The vector meson density matrix elements and hyperon polarization are investigated as functions of momentum transfer. Amplitude analyses are performed for all five reactions. The results are compared with duality and quark model predictions, as well as used to test current ideas in two-body phenomenology. © 1978.