First Flavor-Tagged Determination of Bounds on Mixing-Induced CP Violation in B^0_s --] J/psi Phi Decays

First Flavor-Tagged Determination of Bounds on Mixing-Induced CP Violation in B^0_s --] J/psi Phi Decays
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Total Pages: 11
Release: 2007
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This Letter describes the first determination 1 of bounds on the CP-violation parameter 2[beta]{sub s} using B{sub s}° decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2, 000 B{sub s}° → J/[psi][phi] decays reconstructed in a 1.35 fb−1 data sample collected with the CDFII detector using p{bar p} collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2[beta]{sub s} and the decay-width difference [Delta][Lambda]. Assuming the standard model predictions of 2[beta]{sub s} and [Delta][Lambda], the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.

CP Violation in Flavor-tagged Bs̳ --> J/[psi][phi] Decays

CP Violation in Flavor-tagged Bs̳ --> J/[psi][phi] Decays
Author: Khaldoun Makhoul
Publisher:
Total Pages: 200
Release: 2009
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In this dissertation, we present the results of a time-dependent angular analysis of Bs -+ J/,0 decays performed with the use of initial-state flavor tagging. CP violation is observed in this mode through the interference of decay without net mixing and decay with net mixing, that is, Bs -- J/0 and Bs -+ B, -+ J/q0. The time-dependent angular analysis is used to extract the decay widths of the heavy and light B, eigenstates and the difference between these decay widths AF, - FL - FH. Initial-state flavor tagging is used to determine the matter-antimatter content of the B. mesons at production time. We combine flavor tagging with the angular analysis, which statistically determines the contributions of the CP-even and CP- odd components at decay time, to measure the CP-violating phase 0,. The phase 3, is expressed in terms of elements of the Cabibbo-Kobayashi-Maskawa matrix as s - arg ( -VtsV4/VcsV*b), and is predicted by the Standard Model to be close to zero, O3SM = 0.02. In the measurement of AF, we use a dataset corresponding to 1.7 fb- of luminosity, collected at the CDF experiment from proton-antiproton collisions at a center of mass energy f = 1.96 TeV. In the measurement of Ps, we use a dataset corresponding to 1.3 fb-1 of collected luminosity. We measure AF, = (0.071+0.064 ± 0.007) ps-1 using the time-dependent angular analysis. Combining the angular analysis with flavor-tagging, we find that assuming the Standard Model predictions of p/ and AF, the probability of a deviation as large as the level of the observed data is 33%. We obtain a suite of associated results which are discussed in detail in this dissertation alongside the main results.

CP Violation in {B_s}^0 -> J/psi.phi Decays

CP Violation in {B_s}^0 -> J/psi.phi Decays
Author: Sabato Leo
Publisher: Springer
Total Pages: 146
Release: 2014-07-24
Genre: Science
ISBN: 3319079298
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This thesis reports on the final measurement of the flavor-mixing phase in decays of strange-bottom mesons (B_s) into J/psi and phi mesons performed in high-energy proton-antiproton collisions recorded by the Collider Experiment at Fermilab. Interference occurs between direct decays and decays following virtual particle-antiparticle transitions (B_s-antiB_s). The phase difference between transition amplitudes (“mixing phase”) is observable and extremely sensitive to contributions from non-standard-model particles or interactions that may be very hard to detect otherwise – a fact that makes the precise measurement of the B_s mixing phase one of the most important goals of particle physics. The results presented include a precise determination of the mixing phase and a suite of other important supplementary results. All measurements are among the most precise available from a single experiment and provide significantly improved constraints on the phenomenology of new particles and interactions.

{CP} Violation in Flavor Tagged $B_s \to J/\psi \phi$ Decays

{CP} Violation in Flavor Tagged $B_s \to J/\psi \phi$ Decays
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Total Pages: 200
Release: 2009
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In this dissertation, we present the results of a time-dependent angular analysis of B{sub s} → J/[psi][phi] decays performed with the use of initial-state flavor tagging. CP violation is observed in this mode through the interference of decay without net mixing and decay with net mixing, that is, B{sub s} → J/[psi][phi] and B{sub s} → {bar B}{sub s} → J/[psi][phi]. The time-dependent angular analysis is used to extract the decay widths of the heavy and light B{sub s} eigenstates and the difference between these decay widths [Delta][Lambda]{sub s} {triple_bond} [Lambda]{sub s}{sup L}-[Lambda]{sub s}{sup H}. Initial-state flavor tagging is used to determine the matter-antimatter content of the B{sub s} mesons at production time. We combine flavor tagging with the angular analysis, which statistically determines the contributions of the CP-even and CP-odd components at decay time, to measure the CP-violating phase [beta]{sub s}. The phase [beta]{sub s} is expressed in terms of elements of the Cabibbo-Kobayashi-Maskawa matrix as [beta]{sub s} {triple_bond} arg (-V{sub ts}V*{sub tb}/V{sub cs}V*{sub cb}), and is predicted by the Standard Model to be close to zero, [beta]{sub s}{sup SM} = 0.02. In the measurement of [Delta][Lambda]{sub s}, we use a dataset corresponding to 1.7 fb−1 of luminosity, collected at the CDF experiment from proton-antiproton collisions at a center of mass energy √s = 1.96 TeV. In the measurement of [beta]{sub s}, we use a dataset corresponding to 1.3 fb−1 of collected luminosity. We measure [Delta][Lambda]{sub s} = (0.071{sub -0.059}{sup +0.064} ± 0.007) ps−1 using the time-dependent angular analysis. Combining the angular analysis with flavor-tagging, we find that assuming the Standard Model predictions of [beta]{sub s} and [Delta][Lambda]{sub s}, the probability of a deviation as large as the level of the observed data is 33%. We obtain a suite of associated results which are discussed in detail in this dissertation alongside the main results.

Time-Dependent CP Violation Measurements

Time-Dependent CP Violation Measurements
Author: Markus Röhrken
Publisher: Springer Science & Business Media
Total Pages: 205
Release: 2013-10-17
Genre: Science
ISBN: 3319007262
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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.

Measurement of B0(s) Mixing Parameters from the Flavor-tagged Decay B0(s) ---] J/psi Phi

Measurement of B0(s) Mixing Parameters from the Flavor-tagged Decay B0(s) ---] J/psi Phi
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Total Pages: 7
Release: 2008
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From an analysis of the flavor-tagged decay B{sub s}° 2!J/[psi][phi] they obtain the width difference between the B{sub s}° light and heavy mass eigenstates, [Delta][Lambda]{sub s} {triple_bond} [Lambda]{sub L} - [Lambda]{sub H} = 0.19 ± 0.07(stat){sub -0.01}{sup +0.02}(syst) ps−1, and the CP-violating phase, [phi]{sub s} = -0.57{sub -0.30}{sup +0.24}(stat){sub -0.02}{sup +0.07}(syst). The allowed 90% C.L. intervals of [Delta][Lambda]{sub s} and [phi]{sub s} are 0.06

Search for CP Violation in B0s to Jpsi Phi

Search for CP Violation in B0s to Jpsi Phi
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Total Pages: 192
Release: 2008
Genre:
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The CDF experiment, which uses p{bar p} collisions at √s = 1.9 TeV produced at the Fermilab Tevatron, is unique in its ability to observe all flavors of B hadrons and measure their properties. Among them, CP violation is of fundamental interest. In the B+ and B° systems, measurements of CP violation parameters performed essentially at B factories have borne out the predictions of CKM model. Little is known, experimentally, about CP violation in the B{sub s}° system. The standard model predicts very little CP violation there, thus any nonzero measurement could be an indication of new physics. In this thesis, we will report on the very first flavor-tagged analysis of approximately 2000 B{sub s}° → J/[psi][phi] decays reconstructed in a 1.35 fb−1 data sample collected at CDF. This channel is sensitive not only to the width difference [Delta][Lambda] in the B{sub s}° system but also to the CP violation parameter [beta]{sub s}. The final result we obtain is a confidence region in the two dimensional space of [beta]{sub s} and [Delta][Lambda]. Assuming the standard model predictions of [beta]{sub s} and [Delta][Lambda], the probability is 15%, corresponding to 1.5 Gaussian standard deviations.