Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to Eta K Gamma

Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to Eta K Gamma PDF Author:
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ISBN:
Category :
Languages : en
Pages : 7

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Book Description
The authors present measurements of the CP-violation parameters S and C for the radiative decay B° →?K{sub S}°?; for B →?K? they also measure the branching fractions and for B →?K+? the time-integrated charge asymmetry?{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 106 B{bar B} pairs produced in e+e− annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} ± 0.12, C = -0.32{sub -0.39}{sup +0.40} ± 0.07,?(B° →?K°?) = (7.1{sub -2.0}{sup +2.1} ± 0.4) x 10−6,?(B+ →?K+?) = (7.7 ± 1.0 ± 0.4) x 10−6, and?{sub ch} = ( -9.0{sub -9.8}{sup +10.4} ± 1.4) x 10−2. The first error quoted is statistical and the second systematic.

Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to Eta K Gamma

Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to Eta K Gamma PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

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Book Description
The authors present measurements of the CP-violation parameters S and C for the radiative decay B° →?K{sub S}°?; for B →?K? they also measure the branching fractions and for B →?K+? the time-integrated charge asymmetry?{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 106 B{bar B} pairs produced in e+e− annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} ± 0.12, C = -0.32{sub -0.39}{sup +0.40} ± 0.07,?(B° →?K°?) = (7.1{sub -2.0}{sup +2.1} ± 0.4) x 10−6,?(B+ →?K+?) = (7.7 ± 1.0 ± 0.4) x 10−6, and?{sub ch} = ( -9.0{sub -9.8}{sup +10.4} ± 1.4) x 10−2. The first error quoted is statistical and the second systematic.

Measurement of Branching Fractions in Radiative BDecays to Eta K Gamma and Search for B Decays to Eta' K Gamma

Measurement of Branching Fractions in Radiative BDecays to Eta K Gamma and Search for B Decays to Eta' K Gamma PDF Author: B. Aubert
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

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Book Description
The authors present measurements of the B {yields} {eta}K{gamma} branching fractions and upper limits for the B {yields} {eta}'K{gamma} branching fractions. For B{sup +} {yields} {eta}K{sup +}{gamma} they also measure the time-integrated charge asymmetry. The data sample, collected with the BABAR detector at the Stanford Linear Accelerator Center, represents 232 x 10{sup 6} produced B{bar B} pairs. The results for branching fractions and upper limits at 90% C.L. in units of 10{sup -6} are: {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = 11.3{sub -2.6}{sup +2.8} {+-} 0.6, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = 10.0 {+-} 1.3 {+-} 0.5, {Beta}(B{sup 0} {yields} {eta}'K{sup 0}{gamma})

Measurements of Branching Fractions and Time-Dependent CP-Violating Asymmetries in B to Eta' K Decays

Measurements of Branching Fractions and Time-Dependent CP-Violating Asymmetries in B to Eta' K Decays PDF Author:
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Category :
Languages : en
Pages :

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Measurement of the Branching Fraction and Search for Direct CP-Violation in the Radiative Decay B to K*Gamma with the BABAR Detector

Measurement of the Branching Fraction and Search for Direct CP-Violation in the Radiative Decay B to K*Gamma with the BABAR Detector PDF Author:
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Category :
Languages : en
Pages :

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The presented study of the radiative electroweak "penguin"--Decay B->K*(892)gamma, proceeding by the b->sgamma "loop"-transition, provides an important test of the Standard Model and a candidate of the search for New Physics. The used data sample has been recorded at the Y(4S) resonance with the BABAR detector at the asymmetric electron-positron- collider PEP-II of the Stanford Linear Accelerator Center (SLAC) in California. The B->K*gamma branching fractions are measured in four K*-decay modes. A search for direct CP-violation in the B->K*gamma mode has also been carried out.

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 PDF Author:
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ISBN:
Category :
Languages : en
Pages : 12

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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 Fraction and CP Violation InB Meson Rare Decays to Final States Containing Eta Or Eta' Mesons in the BaBar Experiment at SLAC.

Measurements of Branching Fraction and CP Violation InB Meson Rare Decays to Final States Containing Eta Or Eta' Mesons in the BaBar Experiment at SLAC. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 383

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Book Description
Note that the main goal of this thesis work is the measurement of the branching fractions, charge asymmetry, and Time-Dependent CP Violation in [eta]'K° mode. All other measurements are reported here for completion because they are connected by similar physics arguments. They are part of the Milan analysis activity, done by undergraduate students. They should not be considered as done in this thesis work. The measurements of the two body-modes [eta][eta], [eta][phi], and [eta]'[phi] are used to determine a theoretical bound based on SU(3) flavor symmetry for the difference between SM prediction and the experimental measurements of CP violation parameters in b → s loop-dominated modes. In general for this estimation we need to measure the branching fractions (or upper limits) of neutral B decays to two-body modes with [eta]', [eta], [phi], [omega], [pi]°, K°, K*° [13, 14, 15, 16]. There is an important issue related to the branching fractions of [eta]'K (charged and neutral) modes. Since the discover of B → [eta]'K in 1997 [17] with high branching fraction (higher than expected), it was found that the corresponding mode with [eta] is suppressed. This fact was pointed out by Lipkin in 1991 [18]. In particular, using arguments concerning the [eta]-[eta]' mixing angle and the parity of K or K* we can say that [eta]'K and [eta]K* are enhanced, while [eta]K and [eta]'K* are suppressed. This scheme is experimentally verified. The branching fraction of all these modes are already measured, but the B° → [eta]K°. So it is important to measure also this mode to complete the scenario. Finally we report on the measurements of the radiative modes B → [eta]'K[gamma] and of the three-body mode B → [eta]'[eta]'K. Both cases are good candidates to manifest effects due to NP in CP violations [19, 20]. For all measurements we use an unbinned maximum likelihood fit to extract the number of signal yields and CP parameters. To perform these fits we have developed a flexible program in C++ language, called MiFit, which has taken a consistent part of the work described in this thesis. This program is used in all Milan analyses. All these measurements have been presented in conferences and published in Physical Review Letters or Physics Review D (Rapid Communication). These measurements are official BABAR results, approved by the Collaboration. The thesis is structured in eight chapters. In the first chapter we describe the CP violation and how it is explained in the SM. We give the theoretical description of the modes studied in this thesis. We report also the latest main results for the CP violation. In the second chapter we describe the BABAR detector with a description of each sub-detector. In the third chapter we describe the software used by the collaboration, in particular the code used in the events reconstruction, which is described in the fourth chapter. In the fifth chapter we describe the software used to selected the events and the MiFit program. After that, in the sixth chapter we show the discriminating variables used for the events selection and how the selection is done. In the last two chapters we report the analyses and results of the branching fractions and charge asymmetries measurements and the time-dependent CP asymmetries analysis of the mode B° → [eta]'K°, respectively.

B Physics And Cp Violation: Proceedings Of The 2nd International Conference

B Physics And Cp Violation: Proceedings Of The 2nd International Conference PDF Author: Thomas E Browder
Publisher: World Scientific
ISBN: 9814602760
Category :
Languages : en
Pages : 528

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Book Description
CP violation is one of the most subtle effects in the Standard Model of particle physics and may be the first clue to the physics that lies beyond. Charge conjugation, C, and parity, P, are symmetries of particle interactions. C corresponds to the operation of replacing a particle by its antiparticle, while P is the operation of mirror reflection. Before 1956, it was believed that these were also symmetries of the interactions of elementary particles. In 1956, C S Wu found evidence for P violation in the weak interaction. Theorists proposed that the combination of CP would be a symmetry of the weak interaction. In 1964, Christenson, Cronin, Fitch and Turlay found the first evidence for the violation of CP symmetry in the decays of kaons.Although Kobayashi and Maskawa then showed how the Standard Model can accommodate the observed CP violation, Wolfenstein pointed out that it is also possible that there is a new interaction in addition to the usual four, called the superweak interaction, which is responsible for the asymmetry. To test this idea, the observation of a different type of asymmetry, called direct CP violation, is required; in the kaon sector, very precise measurements of the ratio of kaon decay rates are necessary. In B decay modes where a second order weak process whimisically named “penguin” interferes with another suppressed, first order “tree” amplitude, it may also be possible to observe these direct CP-violating effects.B physics and CP violation is now one of the major growth areas in high energy physics. Nearly every major high energy physics laboratory now has a project underway to observe the large CP asymmetries expected in the B sector and to test the consistency of the Standard Model. The unitarity of the Kobayashi-Maskawa mixing matrix in the Standard Model implies the existence of three phases, called alpha, beta and gamma, which can be determined by the measurements of CP asymmetries in B decays. About 200 participants gathered in Hawaii in March 1997 to discuss the progress in the field, and this important book constitutes the proceedings of that conference.

Measurements of the Branching Fraction and CP-Violating Asymmetries of B[sup 0]--] K[sup 0][pi][sup 0] Decays

Measurements of the Branching Fraction and CP-Violating Asymmetries of B[sup 0]--] K[sup 0][pi][sup 0] Decays PDF Author:
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Category :
Languages : en
Pages :

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No abstract prepared.

Legge sul diritto di bollo, 13 novembre 1899

Legge sul diritto di bollo, 13 novembre 1899 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Measurements of B -] V Gamma Decays

Measurements of B -] V Gamma Decays PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 217

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Book Description
The standard model has been highly successful at describing current experimental data. However, extensions of the standard model predict particles that have masses at energy scales that are above the electroweak scale. The flavor-changing neutral current processes of the B meson are sensitive to the influences of these new physics contributions. These processes proceed through loop diagrams, thus allowing new physics to enter at the same order as the standard model. New physics may contribute to the enhancement or suppression of rate asymmetries or the decay rates of these processes. The transition B → V[gamma] (V = K*(892), [rho](770), [omega](782), [phi](1020)) represents radiative decays of the B meson that proceed through penguin processes. Hadronic uncertainties limit the theoretical accuracy of the prediction of the branching fractions. However, uncertainties, both theoretical and experimental, are much reduced when considering quantities involving ratios of branching fractions, such as CP or isospin asymmetries. The most dominant exclusive radiative b → s transition is B → K*[gamma]. We present the best measurements of the branching fractions, direct CP, and isospin asymmetries of B → K*[gamma]. The analogous b → d transitions are B → [rho][gamma] and B → [omega][gamma], which are suppressed by a factor of.