Plasma-Wakefield Accelerator Group

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.