Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays

Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays PDF Author:
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Languages : en
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Book Description
We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 227 x 106 [Upsilon](4S) → B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The amplitude of the CP asymmetry, sin2[beta] in the Standard Model, is derived from decay-time distributions from events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B° or {bar B}° from its decay products. We measure sin2[beta] = 0.722 ± 0.040(stat) ± 0.023(syst) in agreement with the Standard Model expectation.

Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays

Improved Measurement of CP Asymmetries in B0 to (ccbar)K0(*) Decays PDF Author:
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Languages : en
Pages :

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Book Description
We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 227 x 106 [Upsilon](4S) → B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The amplitude of the CP asymmetry, sin2[beta] in the Standard Model, is derived from decay-time distributions from events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B° or {bar B}° from its decay products. We measure sin2[beta] = 0.722 ± 0.040(stat) ± 0.023(syst) in agreement with the Standard Model expectation.

Improved Measurement of CP Observables in B- to D0_CP K- Decays

Improved Measurement of CP Observables in B- to D0_CP K- Decays PDF Author:
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Languages : en
Pages : 8

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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 both a non-CP flavor eigenstate and in CP (CP-even and CP-odd) eigenstates, based on a sample of 382 million [Upsilon](4S) 2!B{bar B} decays collected with the BABAR detector at the PEP-II ee− storage ring. We measure the direct CP asymmetries A{sub CP±} and the ratios of the branching fractions R{sub CP±}: A{sub CP+} = 0.27 ± 0.09(stat) ± 0.04(syst), A{sub CP-} = -0.09 ± 0.09(stat) ± 0.02(syst), R{sub CP+} = 1.06 ± 0.10(stat) ± 0.05(syst), R{sub CP-} = 1.03 {+-} 0.10(stat) {+-} 0.05(syst). These results will help to better constrain the gamma phase parameter of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Improved Measurements of CP-Violating Asymmetries in B[sup 0] --] [pi][sup +][pi][sup -] Decays

Improved Measurements of CP-Violating Asymmetries in B[sup 0] --] [pi][sup +][pi][sup -] Decays PDF Author:
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Languages : en
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Book Description
The authors present preliminary updated measurements of the CP-violating parameters S[sub [pi][pi]] and C[sub [pi][pi]] in B[sup 0] --> [pi][sup +][pi][sup -] decays. Using a sample of 227 million [Upsilon](4S) --> B[bar B] decays collected with the BaBar detector at the PEP-II asymmetric-energy e[sup +]e[sup -] collider at SLAC, they observe 467 [+-] 33 signal decays and measure S[sub [pi][pi]] = -0.30 [+-] 0.17(stat)[+-] 0.03(syst), and C[sub [pi][pi]] = -0.09 [+-] 0.15(stat)[+-] 0.04(syst).

Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays

Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays PDF Author:
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Category :
Languages : en
Pages : 27

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Book Description
The authors present preliminary results of improved measurements of the CP-violating asymmetries and branching fractions in the decays B° →??−, B° → K+?−, B° →?°?°, and B° → K°?°. This update includes all data taken at the?(4S) resonance by the BABAR experiment at the asymmetric PEP-II B-meson factory at SLAC, corresponding to 467 ± 5 million B{bar B} pairs. They find S{sub??} = -0.68 ± 0.10 ± 0.03, C{sub??} = -0.25 ± 0.08 ± 0.02,?{sub K{sub?}} = -0.107 ± 0.016{sub -0.004}, {sup +0.006}, C{sub?°?°} = -0.43 ± 0.26 ± 0.05,?(B° →?°?°) = (1.83 ± 0.21 ± 0.13) x 10−6,?(B° → K°?°) = (10.1 ± 0.6 ± 0.4) x 10−6, where the first error is statistical and the second is systematic. They observe CP violation with a significance of 6.7? in B° → {pi}− and 6.1? in B° → K+{pi}−. Constraints on the Unitarity Triangle angle? are determined from the isospin relation between all B → {pi}{pi} rates and asymmetries.

Improved Measurement of CP Violation in Neutral BDecays to \ccbar S

Improved Measurement of CP Violation in Neutral BDecays to \ccbar S PDF Author:
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ISBN:
Category :
Languages : en
Pages : 7

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Book Description
The authors present updated measurements of time-dependent CP asymmetries in fully-reconstructed neutral B decays to several CP eigenstates containing a charmonium meson. The measurements use a data sample of (383 ± 4) x 106 [Upsilon](4S) → B{bar B} decays collected with the BABAR detector at the PEP-II B factory. They determine sin2[beta] = 0.714 ± 0.032(stat) ± 0.018(syst) and.

Measurement of CP Asymmetries in B0-]Ks Pi0 Pi0 Decays

Measurement of CP Asymmetries in B0-]Ks Pi0 Pi0 Decays PDF Author: J. C. Chen
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ISBN:
Category :
Languages : en
Pages : 17

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Book Description
The authors present a preliminary measurement of the time-dependent CP asymmetry for the neutral B-meson decay into the CP = +1 final state K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}, with K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -} and {pi}{sup 0} {yields} {gamma}{gamma}. They use a sample of approximately 227 million B-meson pairs recorded at the {Upsilon}(4S) resonance by the BABAR detector at the PEP-II B-Factory at SLAC. From a maximum likelihood fit they extract the mixing-induced CP-violation parameter S{sub K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}} = 0.84 {+-} 0.71(stat) {+-} 0.08(syst) and the direct CP-violation parameter C{sub K{sub S}{sup 0}}{pi}{sup 0}{pi}{sup 0} = 0.27 {+-} 0.52(stat) {+-} 0.13(syst), where the first uncertainty is statistical and the second systematic.

Measurement of CP Asymmetries in B0 to Phi K0 and B0 to K+K-Ks Decays

Measurement of CP Asymmetries in B0 to Phi K0 and B0 to K+K-Ks Decays PDF Author:
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Category :
Languages : en
Pages :

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Book Description
We measure the time-dependent CP asymmetry parameters in B° 2!KK−K° based on a data sample of approximately 227 million B-meson pairs recorded at the [Upsilon](4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. We reconstruct two-body B° decays to [phi](1020)K{sub s}° and [phi](1020)K{sub L}°, and the three-body decay KK−K{sub s}° with [phi](1020)K{sub s}° excluded. For the B° 2![phi]K° decays, they measure sin 2[beta]{sub eff}([phi]K°) = +0.50 ± 0.25(stat){sub -0.04}{sup +0.07}(syst). The B° 2!K+K−K{sub s}° decays are dominated by K+K− S-wave, as determined from an angular analysis; they measure sin 2[beta]{sub eff} (K+K−K{sub s}°) = +0.55 ± 0.22(stat) ± 0.04(syst) ± 0.11(CP), where the last error is due to the uncertainty in the fraction of CP-even contributions to the decay amplitude. We find no evidence for direct CP violation.

Improved Measurement of the CP-Violating Asymmetry Amplitude Sin2beta

Improved Measurement of the CP-Violating Asymmetry Amplitude Sin2beta PDF Author:
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Category :
Languages : en
Pages :

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Book Description
We present updated results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 62 million [Upsilon](4S) [yields] B[bar B] decays collected between 1999 and 2001 by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. In this sample we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2[beta], is derived from the decay time distributions in such events. We measure sin2[beta] = 0.75 [+-] 0.09 (stat) [+-] 0.04 (syst) and lambda = 0.92 [+-] 0.06 (stat) [+-] 0.02 (syst). The latter is consistent with the Standard Model expectation of no direct CP violation. These results are preliminary.

Measurements of Time-dependent CP Asymmetries in B0 --] D(*)+D(*)- Decays

Measurements of Time-dependent CP Asymmetries in B0 --] D(*)+D(*)- Decays PDF Author:
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Languages : en
Pages : 13

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Book Description
We present new measurements of time-dependent CP asymmetries for B° --> D{sup (*)+}d{sup (*)-} decays using (467 ± 5) x 106 B{bar B} pairs collected with the BABAR detector located at the PEP-II B Factory at the Stanford Linear Accelerator Center. We determine the CP-odd fraction of the B° --> D*D*− decays to be R(up tack) = 0.158 ± 0.028 ± 0.006 and find CP asymmetry parameters for the CP-even component of the decay S+ = -0.76 ± 0.16 ± 0.04 and C+ = 0.00 ± 0.12 ± 0.02. We measure S = -0.63±0.36±0.05 and C = -0.07±0.23±0.03 for B° --> DD−, S = -0.62±0.21±0.03 and C = 0.08 ± 0.17 ± 0.04 for B° --> D*+D−, and S = -0.73 ± 0.23 ± 0.05 and C = 0.00 ± 0.17 ± 0.03 for B° --> D+D*−. For the B° --> D*{sup ±}D{sup {-+}} decays, we also determine the CP-violating asymmetry A = 0.008 ± 0.048 {+-} 0.013. In each case, the first uncertainty is statistical and the second is systematic. The measured values for the asymmetries are all consistent with the Standard Model.

Measurement of CP Asymmetries and Branching Fractions in B to Pi Pi and B to K Pi Decays

Measurement of CP Asymmetries and Branching Fractions in B to Pi Pi and B to K Pi Decays PDF Author: B. Aubert
Publisher:
ISBN:
Category :
Languages : en
Pages : 24

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Book Description
The authors present preliminary measurements of the Cp asymmetries and branching fractions for B {yields} {pi}{pi} and B {yields} K{pi} decays. A total of 347 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC are used for these results.