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.







Measurement of Ratios of Branching Fractions and CP-Violating Asymmetries of B+/- --] D*K +/- Decays


Book Description

The authors report a study of B{sup ±} 2!D*K{sup ±} decays with D* decaying to D[pi]° or D[gamma], using 383 x 106 B{bar B} pairs collected at the [Upsilon](4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. The D meson decays under study include a non-CP mode (K{sup ±}[pi]{sup {-+}}), CP-even modes (K{sup ±}K{sup {-+}}, [pi]{sup ±}[pi]{sup {-+}}) and CP-odd modes (K{sub S}°[pi]°, K{sub S}°[phi], K{sub S}°[omega]). They measure ratios (R*{sub CP±}) of branching fractions of decays to CP eigenmode states and to flavor-specific states as well as CP asymmetries A*{sub CP±} = -0.11 ± 0.09 ± 0.01, R*{sub CP+} = 1.31 ± 0.13 ± 0.04, and A*{sub CP-} = 0.06 ± 0.10 {+-} 0.02, R*{sub CP-} = 1.10 {+-} 0.12 {+-} 0.04, where the first error is statistical and the second error is systematic. Translating the results into an alternative parameterization, widely used for related measurements, they obtain x*+ = 0.11 {+-} 0.06 {+-} 0.02 and x* = 0.00 {+-} 0.06 {+-} 0.01. No significant CP-violating charge asymmetry is found in either the flavor-specific mode D 2!K{sup {+-}}[pi]{sup {-+}} or in B{sup {+-}} 2!D*[pi]{sup {+-}} decays.




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


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.







Measurement of Branching Fraction Ratios and CP Asymmetries in B -]D0 CPK Decays with the BABAR Detector


Book Description

The primary goals of the BABAR experiment are the detection of CP violation (CPV) in the B meson system, the precise measurement of some of the elements of the CKM matrix and the measurement of the rates of rare B meson decays. At present, BABAR has achieved major successes: (1) the discovery, in neutral B decays, of direct and mixing-induced CP violation; (2) accurate measurements of the magnitudes of the CKM matrix elements.