Evidence for. rho. sub 1 (1270) production in the reaction K sup minus p yields. pi. sup +. pi. sup minus. Lambda
Le résumé fourni par la source
Preliminary results are presented from an analysis of the {pi}{sup +}{pi}{sup {minus}} system produced in the reaction {Kappa}{sup {minus}}p {yields} {pi}{sup +}{pi}{sup {minus}} {Lambda} at 11 GeV/c observed with the LASS spectrometer at SLAC. A clear {rho} --{minus} {omega} interference effect is observed, and a fit to the natural parity exchange mass distribution yields a branching fraction estimate of (1.7 {plus minus} 0.5) % for the decay {omega} {yields}{pi}{sup +}{pi}{sup {minus}}. An amplitude analysis reveals that the bump in the mass distribution in the vicinity of the f{sub 2}(1270) actually contains a significant P-wave component. The mass dependence of the corresponding amplitude and phase is well described by a resonant Breit-Wigner line-shape with mass (1266 {plus minus} 14) MeV/c{sup 2}, width (166 {plus minus} 35) MeV/c{sup 2}, and estimated elasticity {approximately} 5%. The interpretation of this state as the first radial excitation of the {rho}(770) is discussed. 15 refs., 5 figs.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.