› › Measurements Of The Branching Fractions And Cp Asymmetries Of B D0 Cp K Decays

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

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Page : 8 pages

File Size : 30,86 MB

Release : 2006

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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).



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

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Page : 12 pages

File Size : 44,47 MB

Release : 2008

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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].

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Page : pages

File Size : 11,93 MB

Release : 2004

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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

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Page : 8 pages

File Size : 19,14 MB

Release : 2011

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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 the Branching Fractions and CP Asymmetries of B[sup -] --] D[sup 0][sub (CP)]K[sup -] Decays with the BABAR Detector

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Page : pages

File Size : 24,17 MB

Release : 2004

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The authors have reconstructed B[sup -] --> D[sup 0]K[sup -] decays with D[sup 0] mesons decaying to non-CP (K[sup -][pi][sup +]), CD-even (K[sup -]K[sup +], [pi][sup -][pi][sup +]) and CP-odd (K[sup 0][sub s][pi][sup 0]) eigenstates. They have measured the CP asymmetries A[sub CP[sup +]] = 0.40 [+-] 0.15(stat) [+-] 0.08(syst), A[sup CP[sup -]] = 0.21 [+-] 0.17(stat) [+-] 0.07(syst), and the double ratio of branching fractions R[sub +] = 0.87 [+-] 0.14(stat) [+-] 0.06(syst), R[sub -] = 0.80 [+-] 0.14(stat) [+-] 0.08(syst). These results improve the previous existing measurements from BABAR. All results presented in this document are preliminary.







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

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Page : 172 pages

File Size : 16,87 MB

Release : 2010

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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.



Measurements of Branching Fractions and CP Asymmetries in Decays of a B Meson to Two Phi Mesons and a K Meson

Author : Hulya Atmacan

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Page : 195 pages

File Size : 43,30 MB

Release : 2010

Category : B mesons

ISBN : 9781124263076

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We present measurements of the decays B[superscript +] [arrow right] [straight phi][straight phi] K [superscript +] and B[superscript o] [arrow right] [straight phi][straight phi] K [superscript o] using about 464 million BB[superscript -] pairs collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We report the branching fractions of the decays B [superscript +] [arrow right] [straight phi][straight phi] K[superscript +] and B[superscript o] [arrow right] [straight phi][straight phi] K[superscript o], and CP asymmetry in the charged B mode for [straight phi][straight phi] invariant mass below 2.85 GeV/ c 2 : [Special characters omitted.] Additionally, we measure the direct CP asymmetry in B[superscript +] [arrow right] [straight phi][straight phi] K [superscript +] for [straight phi][straight phi] invariant mass within the [eta][subcript c] resonance region ([2.94-3.02] GeV/ c 2): [Special characters omitted.] No direct CP asymmetry is observed both below the [eta][subcript c] and within the [eta][subcript c] resonance, as expected within the Standard Model. In each case the uncertainties are statistical and systematic, respectively.