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

Measurement of Ratios of Branching Fractions and CP-Violating Asymmetries of B+/- --] D*K +/- Decays
Author:
Publisher:
Total Pages: 12
Release: 2008
Genre:
ISBN:

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 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].

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].
Author:
Publisher:
Total Pages:
Release: 2004
Genre:
ISBN:

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

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
Author:
Publisher:
Total Pages: 8
Release: 2011
Genre:
ISBN:

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 CP Violation Observables and Parameters for the Decays $B{̂\pm}\to DK{̂*\pm}$

Measurement of CP Violation Observables and Parameters for the Decays $B{̂\pm}\to DK{̂*\pm}$
Author:
Publisher:
Total Pages: 16
Release: 2010
Genre:
ISBN:

We study the decay B− → DK*− using a sample of 379 x 106?(4S) → B{bar B} events collected with the BABAR detector at the PEP-II B-factory. We perform a 'GLW' analysis where the D meson decays into either a CP-even (CP+) eigenstate (KK−,?+?−), CP-odd (CP- ) eigenstate (K{sub S}°?°, K{sub S}°?, K{sub S}°?) or a non-CP state (K−?+). We also analyze D meson decays into K+?− from a Cabibbo-favored {bar D}° decay or doubly suppressed D° decay ('ADS' analysis). We measure observables that are sensitive to the CKM angle?: the partial-rate charge asymmetries A{sub CP±}, the ratios R{sub CP±} of the B-decay branching fractions in CP± and non-CP decay, the ratio R{sub ADS} of the charge-averaged branching fractions, and the charge asymmetry A{sub ADS} of the ADS decays: A{sub CP+} = 0.09 ± 0.13 ± 0.06, A{sub CP-} = -0.23 ± 0.21 ± 0.07, R{sub CP+} = 2.17 ± 0.35 ± 0.09, R{sub CP-} = 1.03 ± 0.27 ± 0.13, R{sub ADS} = 0.066 ± 0.031 ± 0.010, and A{sub ADS} = -0.34 {+-} 0.43 {+-} 0.16, where the first uncertainty is statistical and the second is systematic. Combining all the measurements and using a frequentist approach yields the magnitude of the ratio between the Cabibbo-suppressed and favored amplitudes, r{sub B} = 0.31 with a one (two) sigma confidence level interval of [0.24, 0.38] ([0.17, 0.43]). The value r{sub B} = 0 is excluded at the 3.3 sigma level. A similar analysis excludes values of? in the intervals [0, 7]{sup o}, [55, 111]{sup o}, and [175, 180]{sup o} ([85, 99]{sup o}) at the one (two) sigma confidence level.

Measurements of Branching Fractions and CP-Violating Asymmetries in B Meson Decays to Charmless Two-Body States Containing a K[sup 0].

Measurements of Branching Fractions and CP-Violating Asymmetries in B Meson Decays to Charmless Two-Body States Containing a K[sup 0].
Author:
Publisher:
Total Pages:
Release: 2004
Genre:
ISBN:

The authors present measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K[sup 0]. The results are based on a data sample of approximately 88 million [Upsilon](4S) [yields] B[bar B] decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.

Measurements of Branching Fractions, Polarizations, and Direct CP-violation Asymmetries in B -] Rho0 K* and B -] F0(980) K* Decays

Measurements of Branching Fractions, Polarizations, and Direct CP-violation Asymmetries in B -] Rho0 K* and B -] F0(980) K* Decays
Author:
Publisher:
Total Pages: 8
Release: 2011
Genre:
ISBN:

We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B →?°K*+ and B+ f0(980)K*+ with a sample of (467 ± 5) x 106 B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+e− collider at the SLAC National Accelerator Laboratory. We observe B+ →?°K*+ with a significance of 5.3? and measure the branching fraction?(B+ →?°K*+) = (4.6 ± 1.0 ± 0.4) x 10−6, the longitudinal polarization f{sub L} = 0.78 ± 0.12 ± 0.03, and the CP-violation asymmetry A{sub CP} = 0.31 ± 0.13 ± 0.03. We observe B+ → f0(980)K*+ and measure the branching fraction?(B+ → f0(980)K*+) x?(f0(980) →?+?−) = (4.2 ± 0.6 ± 0.3) x 10−6 and the CP-violation asymmetry A{sub CP} = -0.15 ± 0.12 ± 0.03. The first uncertainty quoted is statistical and the second is systematic.

MEASUREMENTS OF BRANCHING FRACTIONS AND CP VIOLATING ASYMMETRIES IN B0 ---] PI+ PI-, K+ PI-, K+ K- DECAYS.

MEASUREMENTS OF BRANCHING FRACTIONS AND CP VIOLATING ASYMMETRIES IN B0 ---] PI+ PI-, K+ PI-, K+ K- DECAYS.
Author:
Publisher:
Total Pages:
Release: 2003
Genre:
ISBN:

We present measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons. The results are obtained from a data sample of about 88 million[Upsilon](4S)[yields] B[bar B] decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a time-independent fit we measure the charge-averaged branching fractions[Beta](B[sup 0][yields][pi][sup+][pi][sup -])= (4.7[+-] 0.6[+-] 0.2) x 10[sup -6] and[Beta](B[sup 0][yields] K[sup+][pi][sup -])= (17.9[+-] 0.9[+-] 0.7) x 10[sup -6], where the first uncertainty is statistical and the second is systematic; the 90% confidence level upper limit[Beta](B[sup 0][yields] K[sup+]K[sup -])

Measurement of Branching Fractions and CP-Violating Asymmetries in B0 to K0K0bar and B+ to K0barK+ Decays at the BaBar Experiment

Measurement of Branching Fractions and CP-Violating Asymmetries in B0 to K0K0bar and B+ to K0barK+ Decays at the BaBar Experiment
Author:
Publisher:
Total Pages: 173
Release: 2007
Genre:
ISBN:

Over the last few years, the B factories have established the Cabbibo-Kobayashi-Maskawa mechanism of CP violation in the Standard Model through the study of the decays of B mesons. The focus of Belle and BaBar has now expanded to the search for signatures of new physics beyond the Standard Model, particularly through examination of flavor-changing neutral-current transitions, which proceed through diagrams involving virtual loops. These decays are suppressed in the Standard Model, increasing sensitivity to new-physics effects but decreasing branching fractions. Exploiting large and growing datasets, BaBar and Belle have made many measurements in loop decays where a b quark transitions to an s quark, observing hints of possible deviations from Standard Model expectations in CP-violating measurements.