Study of B-meson decays to ηcK(*), ηc(2S)K(*), and ηcγK(*)

Abstract

We study two-body B -meson decays to a charmonium state ( η c , η c ( 2 S ) or h c ) and a K + or K * 0 ( 892 ) meson using a sample of 349 fb − 1 of data collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. We measure B ( B 0 → η c K * 0 ) = ( 5.7 ± 0.6 ( stat ) ± 0.9 ( syst ) ) × 10 − 4 , B ( B 0 → η c ( 2 S ) K * 0 ) < 3.9 × 10 − 4 , B ( B + → h c K + ) × B ( h c → η c γ ) < 4.8 × 10 − 5 and B ( B 0 → h c K * 0 ) × B ( h c → η c γ ) < 2.2 × 10 − 4 at the 90% C.L., and B ( η c ( 2 S ) → K ¯¯¯¯ K π ) = ( 1.9 ± 0.4 ( stat ) ± 1.1 ( syst ) ) % . We also measure the mass and width of the η c meson to be m ( η c ) = ( 2985.8 ± 1.5 ( stat ) ± 3.1 ( syst ) ) MeV / c 2 and Γ ( η c ) = ( 36.3 + 3.7 − 3.6 ( stat ) ± 4.4 ( syst ) ) MeV .