A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S).

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S). PDF Author:
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Languages : en
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We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb[sup -1] recorded at the[Upsilon](4S) resonance and 3.9 fb[sup -1] off-resonance. One of the neutral B mesons, which are produced in pairs at the[Upsilon](4S), is fully reconstructed in the CP decay modes J/[psi] K[sub S][sup 0], [psi](2S) K[sub S][sup 0], [chi][sub c1] K[sub S][sup 0], J/[psi] K*[sup 0] (K*[sup 0][yields] K[sub S][sup 0][pi][sup 0]) and J/[psi] K[sub L][sup 0], or in flavor-eigenstate modes involving D(*)[pi]/[rho]/[sub 1] and J/[psi] K*[sup 0] (K*[sup 0][yields] K[sup+][pi][sup -]). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B[sup 0]-[bar B][sup 0] oscillation frequency[Delta]m[sub d]are measured with a sample of about 6350 fully-reconstructed B[sup 0] decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds[Delta]m[sub d]= 0.516[+-] 0.016 (stat)[+-] 0.010 (syst) ps[sup -1]. The value of the asymmetry amplitude sin2[beta] is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B[sup 0] decays in the CP-eigenstate modes. We find sin2[beta]= 0.59[+-] 0.14 (stat)[+-] 0.05 (syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter[lambda]= 0.93[+-] 0.09 (stat)[+-] 0.03 (syst), which is consistent with the expectation of[lambda]= 1 for no direct CP violation.

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S).

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S). PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb[sup -1] recorded at the[Upsilon](4S) resonance and 3.9 fb[sup -1] off-resonance. One of the neutral B mesons, which are produced in pairs at the[Upsilon](4S), is fully reconstructed in the CP decay modes J/[psi] K[sub S][sup 0], [psi](2S) K[sub S][sup 0], [chi][sub c1] K[sub S][sup 0], J/[psi] K*[sup 0] (K*[sup 0][yields] K[sub S][sup 0][pi][sup 0]) and J/[psi] K[sub L][sup 0], or in flavor-eigenstate modes involving D(*)[pi]/[rho]/[sub 1] and J/[psi] K*[sup 0] (K*[sup 0][yields] K[sup+][pi][sup -]). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B[sup 0]-[bar B][sup 0] oscillation frequency[Delta]m[sub d]are measured with a sample of about 6350 fully-reconstructed B[sup 0] decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds[Delta]m[sub d]= 0.516[+-] 0.016 (stat)[+-] 0.010 (syst) ps[sup -1]. The value of the asymmetry amplitude sin2[beta] is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B[sup 0] decays in the CP-eigenstate modes. We find sin2[beta]= 0.59[+-] 0.14 (stat)[+-] 0.05 (syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter[lambda]= 0.93[+-] 0.09 (stat)[+-] 0.03 (syst), which is consistent with the expectation of[lambda]= 1 for no direct CP violation.

CP Violation

CP Violation PDF Author: Cecilia Jarlskog
Publisher: World Scientific
ISBN: 9789971505615
Category : Science
Languages : en
Pages : 736

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Book Description
http://www.worldscientific.com/worldscibooks/10.1142/0496

Time-Dependent CP Violation Measurements

Time-Dependent CP Violation Measurements PDF Author: Markus Röhrken
Publisher: Springer
ISBN: 9783319007250
Category : Science
Languages : en
Pages : 0

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Book Description
This thesis describes a high-quality, high-precision method for the data analysis of an interesting elementary particle reaction. The data was collected at the Japanese B-meson factory KEKB with the Belle detector, one of the most successful large-scale experiments worldwide. CP violation is a subtle quantum effect that makes the world look different when simultaneously left and right and matter and antimatter are exchanged. This being a prerequisite for our own world to have developed from the big bang, there are only a few experimental indications of such effects, and their detection requires very intricate techniques. The discovery of CP violation in B meson decays garnered Kobayashi and Maskawa, who had predicted these findings as early as 1973, the 2008 Nobel prize in physics. This thesis describes in great detail what are by far the best measurements of branching ratios and CP violation parameters in two special reactions with two charm mesons in the final state. It presents an in-depth but accessible overview of the theory, phenomenology, experimental setup, data collection, Monte Carlo simulations, (blind) statistical data analysis, and systematic uncertainty studies.

A Study of Time-dependent CP-violating Asymmetries in B0-]J/psiK0S and B0-]psi(2S)K0S Decays

A Study of Time-dependent CP-violating Asymmetries in B0-]J/psiK0S and B0-]psi(2S)K0S Decays PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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We present a preliminary measurement of time-dependent CP-violating asymmetries in B° → J/[psi] K{sub S}° and B° → [psi](2S)K{sub S}° decays recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The data sample consists of 9.0 fb−1 collected at the [Upsilon](4S) resonance and 0.8 fb−1 off-resonance. One of the neutral B mesons, produced in pairs at the [Upsilon](4S), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The time difference between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities and the time resolution function are measured with samples of fully-reconstructed semileptonic and hadronic neutral B final states. The value of the asymmetry amplitude, sin2[beta], is determined from a maximum likelihood fit to the time distribution of 120 tagged B° → J/[psi] K{sub S}° and B° → [psi](2S) K{sub S}° candidates to be sin2[beta] = 0.12 ± 0.37(stat) ± 0.09(syst) (preliminary).

Fortegnelse over de i 1821 ... indskrevne Studenter

Fortegnelse over de i 1821 ... indskrevne Studenter PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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CP Violation

CP Violation PDF Author: I. I. Bigi
Publisher: Cambridge University Press
ISBN: 052184794X
Category : Science
Languages : en
Pages : 506

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Book Description
Why did the matter in our Universe not annihilate itself with antimatter immediately after its creation? The discovery of CP violation may answer this fundamental question and this book presents information and tools necessary to its understanding.

B Physics And Cp Violation: Bcp4 - Proceedings Of The International Workshop

B Physics And Cp Violation: Bcp4 - Proceedings Of The International Workshop PDF Author: T Ohshima
Publisher: World Scientific
ISBN: 9814490776
Category : Science
Languages : en
Pages : 392

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Book Description
This book offers the first strong evidence of the existence of CP violation in neutral B decays extracted from sophisticated B factories in the US and Japan. It also holds out the expectation of rare B decays and D, K physics in the near future. In addition, new physics beyond the Standard Model is described. Both experimental and theoretical points of view are given.

Study of Time-Dependent CP Asymmetry in Neutral B Decays to J/[psi][pi]°

Study of Time-Dependent CP Asymmetry in Neutral B Decays to J/[psi][pi]° PDF Author:
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ISBN:
Category :
Languages : en
Pages : 7

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The authors present the first study of the time-dependent CP-violating asymmetry in B° 2!J/[psi][pi]° decays using ee− annihilation data collected with the BABAR detector at the [Upsilon](4S) resonance during the years 1999-2002 at the PEP-II asymmetric-energy B Factor at SLAC. Using approximately 88 million B{bar B} pairs, the results for the coefficients of the cosine and sine terms of the CP asymmetry are C{sub J/{psi}[pi]°} = 0.38 ± 0.41 (stat) ± 0.09 (syst) and S{sub J/{psi}[pi]°} = 0.05 ± 0.49 (stat) ± 0.16 (syst).

Oscillation Effects and CP-violation in Neutral B-meson Decays

Oscillation Effects and CP-violation in Neutral B-meson Decays PDF Author: Ja. I. Azimov
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Measurements of CP-violating Asymmetries in Neutral B Meson Decays Into Three Kaons

Measurements of CP-violating Asymmetries in Neutral B Meson Decays Into Three Kaons PDF Author: Joshua M. Thompson
Publisher:
ISBN:
Category :
Languages : en
Pages : 182

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Book Description