含有 eta' 介子的二體B介子稀有衰變

Abstract

We present the results of the searches for two body hadronic B meson decays with an eta' meson in the final state. We observe the decay B->eta' D0 and report the first observation of B->eta' D*0, using 140/fb of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e collider. We find the branching fractions to be: BF(B->D0 eta') = [1.14+-0.20(stat.)+0.10-0.13(syst.)] x 10^-4, BF(B->D*0 eta') = [1.21+-0.34(stat.)+-0.22(syst.)] x 10^-4, with significances including systematic uncertainty of 8.9 and 5.3 standard deviations, respectively. Additionally, we report the results for the charmless decays B-> eta' h, with h = K+, K_S and Pi+, using a data set of 350/fb collected with the Belle detector. We find: BF(B->eta' K+) = [6.86+-0.36(stat.)+-0.21(syst.)] x 10^-5, BF(B->eta' K_S) = [5.66+0.36-0.35(stat.)+0.33-0.32(syst.)] x 10^-5, BF(B->eta' Pi+) = [1.73+0.69-0.63(stat.)+0.11-0.10(syst.)] x 10^-6, where the decay including a pion has a significance of 3 sigma. For the charged charmless decays, we search for direct CP violation and find: ACP(B->eta' K+) = 0.029+-0.028(stat.)+0.021(syst.)] x 10^-6, ACP(B->eta' Pi+) = 0.16+0.39-0.38(stat.)+0.02-0.06(syst.)] x 10^-6.