Strangeness production in Pontecorvo reactions on deuterium

Regenfus, C

C. Regenfus, Strangeness production in Pontecorvo reactions on deuterium, NUCL PHYS A, 655(1-2), 1999, pp. 263C-268C

14

INGLESE

Article

Physics

NUCLEAR PHYSICS A

0375-9474 → ACNP

655

1-2

1999

263C - 268C

ISI

0375-9474(19990809)655:1-2<263C:SPIPRO>2.0.ZU;2-3

From a K-S(0) and Lambda enriched data sample the rare Pontecorvo reactions (p) over bar d --> Lambda K-0 and (p) over bar d-->Sigma(0)K(0) were clear ly observed for the first time. Analyses for missing K-L(0) or charged deca ying K-S(0) in the final state show surprisingly similar branching ratios ( approximate to 2.10(-6)) for both reactions. This rules out a description o f these reaction by a two step mechanism and favours strongly a model of a statistically decaying fireball, formed in the annihilation process. From c omparison to the channel (p) over bar d --> p pi(-) open strangeness is fou nd to be produced at a level of 10%. Additional reactions of the Pontecorvo type were identified where the recoiling baryon is a neutron and the meson decays to (KSKS0)-K-0.