Measurements of the Branching Fractions and CP Asymmetries of B -] D0_CP K Decays


Book Description

We present a study of the decay B− 2!D{sub (CP)}° K− and its charge conjugate, where D{sub (CP)}° is reconstructed in CP-even, CP-odd, and non-CP flavor eigenstates, based on a sample of 232 million [Upsilon](4S) 2!B{bar B} decays collected with the BABAR detector at the PEP-II ee− storage ring. We measure the partial-rate charge asymmetries AC{sub CP±} and the ratios R{sub CP±} of the B 2!D° K decay branching fractions as measured in CP± and non-CP D° decays: A{sub CP+} = 0.35 ± 0.13(stat) ± 0.04(syst), A{sub CP-} = -0.06 ± 0.13(stat) ± 0.04(syst), R{sub CP+} = 0.90 ± 0.12(stat) ± 0.04(syst), R{sub CP-} = 0.86 {+-} 0.10(stat) {+-} 0.05(syst).




B Decays (Revised 2nd Edition)


Book Description

This 2nd edition is an extensive update of 'B Decays”. The revisions are necessary because of the extensive amount of new data and new theoretical ideas. This book reviews what is known about b-quark decays and also looks at what can be learned in the future.The importance of this research area is increasing, as evidenced by the approval of the luminosity upgrade for CESR and the asymmetric B factories at SLAC and KEK, and the possibility of experiments at hadron colliders.The key experimental observations made thus far, measurement of the lifetimes of the different B species, B0-B0 mixing, the discovery of “Penguin” mediated decays, and the extraction of the CKM matrix elements Vub and Vcb from semileptonic decays, as well as more mundane results, are described in great detail by the experimentalists who have been closely involved with making the measurements. Theoretical progress in understanding b-quark decays using HQET and lattice gauge techniques are described by theorists who have developed and used these techniques.Synthesizing the experimental and theoretical information, several articles discuss the implications for the “Standard Model” and how further tests can be done using measurements of CP violation in the B system.







Measurements of Branching Fractions and CP-Violating Asymmetries in B-Meson Decays to the Charmless Two-Body States K[sup 0]pi+, K-bar[sup 0]K[sup +], and K[sup 0]K-bar[sup 0].


Book Description

The authors present preliminary measurements of the branching fraction and the CP-violating charge asymmetry in the B[sup +] --> K[sup 0][pi][sup +] decay, and a preliminary measurement of the branching fraction of the B[sup 0] --> K[sup 0][bar K][sup 0] decay. No evidence of direct CP violation in the B[sup +] --> K[sup 0][pi][sup +] mode is observed. The B[sup 0] --> K[sup 0][bar K][sup 0] measurement constitutes the first observation of this decay channel: the probability of obtaining the result assuming the null-signal hypothesis is 3.4 x 10[sup -6]. The authors have also searched for the B[sup +] --> [bar K][sup 0]K[sup +] decay and set an upper limit on its branching fraction at 2.35 x 10[sup -6] at the 90% C.L. The branching-fraction measurements reported here are consistent with previous measurements of the same quantities, but are extracted from a data sample larger by a factor of 2.6.







Measurements of Branching Fraction Ratios and CP-asymmetries in Suppressed B-2!D(2!K+[pi]- )K- and B-2!D(2!K+[pi]- )[pi]- Decays


Book Description

We report the first reconstruction in hadron collisions of the suppressed decays B-2!D(2!K+[pi]- )K- and B-2!D(2!K+[pi]- )[pi]- decays, sensitive to the CKM phase [gamma], using data from 7 fb-1 of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B-2!D(2!K+[pi]- )K- suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K) = [22.0 " 8.6(stat) " 2.6(syst)] x 10-3, R+(K) = [42.6 " 13.7(stat) " 2.8(syst)] x 10-3, R-(K) = [3.8 " 10.3(stat) " 2.7(syst)] x 10-3 as well as the direct CP-violating asymmetry A(K) = -0.82"0.44(stat)"0.09(syst) of this mode. Corresponding quantities for B- 2!D(2!K+[pi]- )[pi]- decay are also reported.