Measurements of branching fractions of Ac plus , E plus η and Ac plus , E plus ηi and asymmetry parameters of Ac+, E+π0, Ac+, E+ η, and Ac plus , E plus ηi
Abstract
We report a study of A+c , E+pi 0, A+c , E+eta, and A+c , E+ eta i using the data sample correspon-ding to an integrated luminosity of 980 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The branching fractions relative to A+c , E+pi 0 are measured as BA+c,E+eta=BA+c,E+pi 0 = 0.25 +/- 0.03 +/- 0.01 and BA+c,E+eta i=BA+c,E+pi 0 = 0.33 +/- 0.06 +/- 0.02.
Using BA+c,E+pi 0 = (1.25 +/- 0.10)%, we obtain BA+c,E+eta = (3.14 +/- 0.35 +/- 0.17 +/- 0.25) x 10-3 and BA+c,E+eta i = (4.16 +/- 0.75 +/- 0.25 +/- 0.33) x 10-3. Here the uncertainties are statistical, systematic, and from BA+c,E+pi 0, respectively.
The ratio of the branching fraction of A+c , E+eta i with respect to that of A+c , E+eta is measured to be BA+c,E+eta i=BA+c,E+eta = 1.34 +/- 0.28 +/- 0.08. We update the asymmetry parameter of A+c , E+pi 0, alpha E+pi 0 = -0.48 +/- 0.02 +/- 0.02, with a considerably improved precision.
The asymmetry parameters of A+c , E+eta and A+c , E+eta i are measured to be alpha E+eta = -0.99 +/- 0.03 +/- 0.05 and alpha E+eta i = -0.46 +/- 0.06 +/- 0.03 for the first time.