Download or read book Mixing and CP Violation in B and D Decays written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard Model predicts sizeable if not even maximal B/sub s/ - anti B/sub s/ mixing; B/sub d/ - anti B/sub d/ mixing is not expected to exceed the one percent level unless top quarks are very heavy (m/sub t/ greater than or equal to 150 GeV). B decays also offer the best opportunity to discover CP violation outside the neutral K system. Employing the standard model one predicts - with reasonable confidence - CP symmetries of up to 20% (or even more in some cases). The branching ratios for the individual exclusive modes of interest are not expected to exceed the 10−3 level in most cases; the identification of such decays poses non-trivial problems. It is shown that by summing intelligently over appropriate classes of decays one can greatly enhance statistics without jeopardizing the signal. Very similar searches can be performed for D decays.
Download or read book Time Dependent CP Violation Measurements written by Markus Röhrken and published by Springer Science & Business Media. This book was released on 2013-10-17 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Mixing and CP Violation in Charm Meson Decays written by and published by . This book was released on 2010 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixing and CP violation (CPV) in the neutral D system were first discussed over thirty years ago but mixing was observed for the first time only very recently. Since then, these observations have been confirmed in other experiments and in other D° decay modes. Unlike the K, B and B{sub s} systems, for which mixing was observed years earlier, the short distance ([Delta]C = 2) amplitude contributing to mixing in the D system arises from box diagrams with down- rather than up-type quarks in the loops. The d and s components are GIM-suppressed, and the b component is suppressed by the small V{sub ub} CKM coupling. In the standard model (SM), therefore, long range, non-perturbative effects, a coherent sum over intermediate states accessible to both D° and {bar D}°, are the main contribution to mixing. These are hard to compute reliably, however. The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D° system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation, either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
Download or read book B Decays written by Sheldon Stone and published by World Scientific. This book was released on 1994 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 2nd edition is an extensive update of "B Decays?. The revisions are necessary because of the extensive amount of new data and new theoretical ideas. This book reviews what is known about b-quark decays and also looks at what can be learned in the future.The importance of this research area is increasing, as evidenced by the approval of the luminosity upgrade for CESR and the asymmetric B factories at SLAC and KEK, and the possibility of experiments at hadron colliders.The key experimental observations made thus far, measurement of the lifetimes of the different B species, B0-B0 mixing, the discovery of ?Penguin? mediated decays, and the extraction of the CKM matrix elements Vub and Vcb from semileptonic decays, as well as more mundane results, are described in great detail by the experimentalists who have been closely involved with making the measurements. Theoretical progress in understanding b-quark decays using HQET and lattice gauge techniques are described by theorists who have developed and used these techniques.Synthesizing the experimental and theoretical information, several articles discuss the implications for the ?Standard Model? and how further tests can be done using measurements of CP violation in the B system.
Download or read book Radiative Correction Mixing and CP Violation in the B Meson System written by Soo-hyeon Nam and published by . This book was released on 2005 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CP Violation in K and B Decays written by and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author reviews basic aspects of the phenomenology of CP violation in the decays of K and B mesons. In particular he discusses the commonly used classification of CP violation--CP violation in the mass matrix, in the interference of mixing with decay, and in the decay amplitude itself--and the related notions of direct and indirect CP violation. These concepts are illustrated with explicit examples. The author also emphasizes the highlights of this field including the clean observables B(K{sub L} → [pi]°[nu]{anti {nu}}) and A{sub CP} (B → J/[Psi]K{sub S}). The latter quantity serves to demonstrate the general features of large, mixing induced CP violation in B decays.
Download or read book Model independent Analysis of B B Mixing and CP Violation in B Decays written by Toru Goto and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of CP Violation Parameters in B Quark Decays to Charm Anticharm Down Quarks Exclusive Decays at the BABAR Experiment written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The BABAR experiment at SLAC provides an opportunity for measurement of CP violation in B decays. A measurement of time-dependent CP violating asymmetries using exclusive B meson decays where the b quark decays to c{bar c}d (including B° 2!D*D*− and B° 2!D*{sup ±}D{sup {-+}} decays) is presented here. This is the first measurement of CP violation in a mode sensitive to the Unitarity Triangle parameter sin2[beta] outside of decays containing charmonium. It provides a comparison to measurements of sin2[beta] using b 2!c{bar c}s, and permits an observation into potential new physics sources of CP violation, such as supersymmetry, via differences between these measurements and those of B° 2!J/[psi] K{sub S}° as statistics of reconstructed neutral B decays to D{sup (*)+} D{sup (*)-} increase. The measured value of the time-dependent CP violating asymmetries are: S = 0.38 ± 0.88(stat) ± 0.12(syst) and C = -0.30 ± 0.50(stat) ± 0.13(syst) for B° 2!D*− D; S = -0.43 ± 1.41(stat) ± 0.23(syst) and C = 0.53 ± 0.74(stat) ± 0.15(syst) for B° 2!D*+ D−; and S = -0.05 ± 0.45(stat) ± 0.05(syst) and C = 0.12 ± 0.30(stat) {+-} 0.05(syst) for B° 2!D*− D+; where S corresponds to CP violation in the interference of mixing and decay and C corresponds to CP violation in decay.
Download or read book B Physics And Cp Violation Bcp4 Proceedings Of The International Workshop written by T Ohshima and published by World Scientific. This book was released on 2001-09-25 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Measurement of CP Violation in B Anti B Mixing on the Recoil of Partially Reconstructed Anti B0 to D L Anti Nu L Using Kaon Tags written by and published by . This book was released on 2011 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: After its formulation in 1960's the Standard Model of Fundamental Interactions has gone through an impressive series of successes, begun with the discovery of neutral weak currents [1] and the experimental observations of the massive carriers of weak interactions, the W± and Z0 bosons [2], [3]. High precision measurements performed at LEP and SLAC test the validity of the theory to an unprecedented level of accuracy and do not show any significant deviations with respect to the Standard Model predictions. One of the attractive features of the Standard Model is the description of the phenomena which violate the matter-antimatter symmetry (CP), and this violation uniquely depends (in the quark sector) on a weak phase in the matrix describing the couplings among different quark flavors. CP-violation was discovered in 1964 as a tiny effect in the mixing of the K0 - $\bar{K}$0 system [12] but, after a few decades of study of the physics of K mesons, no strong confirmation of the Standard Model can be obtained on the mechanism which generates CP-violation. On the other hand the physics of B mesons is suitable for a pretty large number of measurements which can confirm or disprove this aspect of the theory. The main goal of the BABAR and Belle experiments physics program is to test the description of CP-violation and flavor physics mainly from the decays of Bu and Bd mesons. Soon after the beginning of data-taking in 1999, CP-violation was discovered in the interference between mixing and decay in the golden channel B0 → J/[Psi]}K0 [17] [18], while in 2004 a large direct charge asymmetry was observed in the B0 → K+[pi]- channel [16]. There is a third kind of CP-violation which can be exhibited by the Bd - $\bar{B}$d system, the so called CP-violation in mixing. The Standard Model predicts this asymmetry to be small, possibly out of reach of current experiments, but several New Physics models contain new particles and couplings which can enhance it up to detectable levels. In this thesis we search for CP-violation in Bd - $\bar{B}$d mixing at the BABAR experiment. We reconstruct one of the two B mesons produced at the PEP-II electromagnetic collider using the partial reconstruction technique, while the flavor of the other B is inferred by the charge of a kaon identified among its decay products. Given the smallness of the physical asymmetry we want to measure, a crucial aspect of this analysis is the control of spurious charge asymmetries arising from the interaction of particles with the detector material. We accomplish this by using a control sample of charged kaons on the same data we use in our analysis. After a brief introduction of the theoretical framework and the phenomenology of the decays of B mesons at a B-factory (chapters 1 and 2), we will review in chapter 3 the current experimental results on this topic. We will then describe the characteristics of the collider and the experimental apparatus (chapter 4) used to perform our measurement. The available dataset and the event pre-selection techniques are treated in chapter 5, while the analysis method is discussed in detail in the following one. In chapters 7 and 8 the definitions of the probability density functions used to model each component of our sample are given and then they are tested in samples of simulated data. Toy and reweighted Monte Carlo data are used in chapter 9 to test the sensitivity of our fitting procedure to the physical parameters related to CP violation; chapter 10 discusses the possibility of modeling some of the components of our sample directly on the data. Finally the fit on the real data sample is described in chapter 11 and the treatment of systematic uncertainties is done in chapter 12, while the final result is given in chapter 13.
Download or read book Measurement of Neutral B Neutral B mixing and Studies of the Feasibility of Measuring CP Violation in B to D Pi Decays written by Yangheng Zheng and published by . This book was released on 2002 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing and CP Violation at the Tevatron written by and published by . This book was released on 2008 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of meson mixing and CP violation parameters obtained by the CDF and D0 experiments at the Fermilab Tevatron are presented. These include results on B{sub s} and D meson mixing, and searches for CP violation in the decay B 2!J/[psi]K, in mixing through semileptonic B{sub s} meson decays, and in the interference between mixing and decay in the process B{sub s} 2!J/[psi][phi].
Download or read book Measurement of CP Violation in B0d Mixing Using B0d 2 D mu nu mu X Decays written by and published by . This book was released on 2012 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the measurement of the time-integrated semileptonic charge asymmetry in B0d mixing, ad sl, using the decay chain of B0d! D*-[mu]+([nu][mu]), D*-! D0[pi]-, D0! K+[pi]-. Decay candidates are reconstructed from 10.4 fb-1 of data recorded by the DØ detector at Fermilab's Tevatron p$\bar{p}$ collder during the 2002- 2011 'RunII' data taking period. Yields are extracted using a 2 minimising simultaneous binned fit where 490k D candidates are reconstructed. The measurements presented in this thesis was made possible due to sophisticated online and offline reconstruction software, precise tracking systems, and the first-order background asymmetry negating magnet polarity reversal of the DØ detector.
Download or read book Measurement of CP Violation in Bo d Mixing Using Bo d D v X Decays written by Anthony Ross and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CP Violation in B Meson Decays written by Livio Lanceri and published by . This book was released on 2005 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: CP violation is intimately connected with the puzzle of matter-antimatter asymmetry and baryogenesis. In the Standard Model of particle physics, the observed CP violation phenomena are accounted for by the Cabibbo-Kobayashi-Maskawa mechanism involving a phase in the quark mixing matrix. This paper is devoted to a review of the experimental status of CP violation in the decays of B mesons.
Download or read book Measurements of CP Violation Mixing and Lifetimes of B Mesons with the BaBar Detector written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the observation of CP violation in the B[sup 0] meson system. Using a novel technique for time-dependent measurements, we measure a non-zero value for the CP-violating amplitude sin2[beta] at the 4.1[sigma] level. We also report on precision measurements of the B[sup+] and B[sup 0] lifetimes and the B[sup 0][bar B][sup 0] mixing frequency[Delta]m[sub d] obtained with the same technique, and on a first measurement of the time-dependent CP-violating amplitude in B[sup 0][yields][pi][sup+][sup -] decays.
Download or read book CP Violation and Mixing in Charm Meson Decays from BaBar written by and published by . This book was released on 2011 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixing and CP violation in charm meson decays provide a unique probe of possible physics beyond the standard model. In this paper, we give a brief review of the current measurements from the BABAR experiment.
