Branching Fraction Measurements of the Decays B right arrow n(sub c) K. where n(sub c) K overline K pi and n(sub c) right arrow 4 K

摘要

In this report, we present the observation of the exclusive decays B (sup 0) right arrow n (sub c) K(sup 0) and B (sup +) right arrow n (sub c) K(sup +) and the measurement of the related branching fractions. Using a sample of 22.7 X 10 to the 6th power gamma(4S) right arrow B overline B decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 1999- 2000, we have observed statistically significant signals in the nc right arrow K0 SK+ or - pi + or - and K+K-pi0 channels and set upper limits in the nc right arrow K+K.K+K- channels. All the results presented are preliminary. We have measured B(B+ cK+) = (1.50 + or -- 0.19 + or - 0.15 + or - 0.46) times 10 to the third power B(B0 cK0) =(1.06 + or - 0.28 + or - 0.11 + or - 0.33) times 10 to the third power where the first error is statistical, the second systematic and the last due to the uncertainty on the world average nc right arrow K overline Kpi branching fraction.