Download or read book New Measurements of CP Violation in B0 to Ccbar K 0 Decays from Babar written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Time Dependent CP Violation in Radiative B Decays at BaBar written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present measurements of the CP-violation parameters S and C for the radiative decays B° →?°K{sub S}°? and B° →?K{sub S}°?; for B →?K? they also measure the branching fractions and for B →?K+? the time-integrated charge asymmetry A{sub ch}. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent 467 x 106 B{bar B} pairs produced in e+e− annihilation at the PEP-II collider. In this summary they present an updated measurement of the time-dependent CP asymmetry in B° →?°K{sub S}°? decay mode and the first measurement of the time-dependent CP asymmetry in B° →?K{sub S}°? decay mode. Hadronic corrections in B° →?°K{sub S}°? decay mode might permit S to be as large as ± 0.1. Such corrections and NP effects could depend on m(?°K{sub S}°), so they split the data into two parts: the K*(892) region with 0.8
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 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[sup 0][yields] D*[sup+]D*[sup -] and B[sup 0][yields] 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[yields] 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[sup 0][yields] J/[psi] K[sub S][sup 0] 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[sup 0][yields] D*[sup -] D[sup+]; S= -0.43[+-] 1.41(stat)[+-] 0.23(syst) and C= 0.53[+-] 0.74(stat)[+-] 0.15(syst) for B[sup 0][yields] D*[sup+] D[sup -]; and S= -0.05[+-] 0.45(stat)[+-] 0.05(syst) and C= 0.12[+-] 0.30(stat)[+-] 0.05(syst) for B[sup 0][yields] D*[sup -] D[sup+]; 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 CP Violation in B to S Penguin Decays at BaBar written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CP Violation in B Decays and the BaBar Experiment written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the first year of data taking, the 1999-2000 run, the BABAR detector at the SLAC PEP-II asymmetric collider has collected an integrated luminosity of 20.7 fb[sup -1] corresponding to 22.7 million B[bar B] pairs at the[Upsilon](4S) resonance. Using this data, we present the measurement of sin2[beta] based on samples of B[sup 0][yields] J/[psi] K[sub S][sup 0], B[sup 0][yields][psi](2S) K[sub S][sup 0] and B[sup 0][yields] J/[psi] K[sub L][sup 0] L decays. Our measured value is sin2[beta]= 0.34[+-] 0.20 (stat)[+-] 0.05 (syst). In addition we report on the measurement of branching fractions for exclusive B decays to charmonium final states, measurements of charged and neutral B meson lifetimes and also the B[sup 0][bar B][sup 0] oscillation frequency.
Download or read book CP Violation Measurements in B to Charm Decays at BaBar written by Katherine A. George and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article summarizes measurements of time-dependent CP asymmetries in decays of neutral B mesons to charm final states using data collected by the BABAR detector at the PEP-II asymmetric-energy B factory. All results are preliminary unless otherwise stated.
Download or read book Measurements of CP Violating Asymmetries in the Decay B0 to K K K0 written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors analyze the decay B° 2!KK−K° using 383 million B{bar B} events collected by the BABAR detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all KK−K° events, they find A{sub CP} = -0.015 ± 0.077 ± 0.053 and [beta]{sub eff} = 0.352 ± 0.076 ± 0.026 rad, corresponding to a CP violation significance of 4.8[sigma]. A second solution near [pi]/2 - [beta]{sub eff} is disfavored with a significance of 4.5[sigma]. They also report A{sub CP} and [beta]{sub eff} separately for decays to [phi](1020)K°, f0(980)K°, and K+K−K° with m{sub K{sup +}K−}> 1.1 GeV/c2.
Download or read book CP Violation B Mixing and B Lifetime Results from the BaBar Experiment written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The BABAR detector at the PEP-II asymmetric B Factory at SLAC collected a sample of 23 x 10[sup 6] B[bar B] pairs in the years 1999 and 2000. Using this data sample, we measure the amplitude of the time-dependent CP-violating asymmetry in neutral B decays to the CP eigenstates J/[psi] K[sub S][sup 0], [psi](2S) K[sub S][sup 0] and J/[psi] K[sub L][sup 0]. We find a value of sin2[beta]= 0.34[+-] 0.20(stat)[+-] 0.05(syst). We also present preliminary measurements of the B[sup 0][bar B][sup 0] oscillation frequency and of the lifetimes of charged and neutral B mesons.
Download or read book Measurement of Branching Fractions and CP Violating Asymmetries in B0 to K0K0bar and B to K0barK Decays at the BaBar Experiment written by and published by . This book was released on 2007 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few years, the B factories have established the Cabbibo-Kobayashi-Maskawa mechanism of CP violation in the Standard Model through the study of the decays of B mesons. The focus of Belle and BaBar has now expanded to the search for signatures of new physics beyond the Standard Model, particularly through examination of flavor-changing neutral-current transitions, which proceed through diagrams involving virtual loops. These decays are suppressed in the Standard Model, increasing sensitivity to new-physics effects but decreasing branching fractions. Exploiting large and growing datasets, BaBar and Belle have made many measurements in loop decays where a b quark transitions to an s quark, observing hints of possible deviations from Standard Model expectations in CP-violating measurements.
Download or read book Observation of Direct CP Violation in B sup 0 K sup pi sup Decays written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present an updated search for direct CP violation in the decay B[sup 0] --> K[sup +]pi[sup -]. Using 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, the authors observe a total signal yield of n(K-pi[sup +]) + n(K[sup +]pi[sup -]) = 1606 [+-] 51 decays and measure the asymmetry [n(K[sup -]pi[sup +])-n(K[sup +]pi[sup -])]/[n(K[sup -]pi[sup +])+n(K[sup +]pi[sup -])] = 0.133 [+-] 0.030(stat) [+-] 0.009(syst). This measurement establishes direct CP violation in the B[sup 0] meson system at the level of 4.2 standard deviations.
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 A Measurement of the CP Parameter Sine Two Beta Using Fully Reconstructed B to Ccbar Decays at the BABAR Experiment written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a measurement of the time-dependent CP-violating asymmetries in the neutral B-meson system performed with data collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample used consists of 29.7 fb[sup -1] collected at the[Upsilon](4S) resonance and 3.9 fb[sup -1] collected off-resonance. We analyze three samples of fully-reconstructed B-meson decays: a sample of decays to CP eigenstates in the modes J/[psi] K[sub s][sup 0], [psi](2S) K[sub s][sup 0], [chi][sub cl] K[sub s][sup 0], and J/[psi] K*[sup 0] (822 events); as well as both charged (14304 events) and neutral (10457 events) B decays to flavor-eigenstates including D[sup (*)] and[pi]/[rho]/[alpha][sub 1]. In all cases, the proper decay time difference between the reconstructed B-meson and the recoiling B-meson is determined by measuring the separation of the two decay vertices. Furthermore, the flavor of the recoiling B-meson is tagged using a neural network algorithm. We use the flavor-eigenstate samples to calibrate both the vertexing and tagging performance. We measure the amplitude of the CP asymmetry, sin2[beta]= 0.61[+-] 0.14(stat)[+-] 0.06(syst). These results indicate the existence of indirect CP violation in the B-meson system.
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 Searches for New Physics in CP Violation from BaBar written by and published by . This book was released on 2015 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of recent searches for new physics in CP violation in charm decays from the BABAR experiment are presented. These results include a measurement of D0 - anti D0 mixing and searches for CP violation in two-body D0 decays, a search for CP violation in the charm decays D" 2!KS0K " and D s" 2!KS0K", KS0[pi]", and a search for direct CP violation in the singly-Cabibbo suppressed D" 2!K+K-[pi]"decays. These studies are based on the fi nal dataset collected by BABAR at the PEP-II B factory at SLAC in the period 1999-2008. No evidence of CP violation is found in these charm decays. The measured mixing parameter yCP = [0.72 " 0.18(stat) " 0.12(syst)]% excludes the no-mixing null hypothesis with a signifi cance of 3.3[sigma].
Download or read book Measurement of CP Violation Parameters in B Ccd Exclusive Decays at the BABAR Experiment written by Justin E. Albert and published by . This book was released on 2002 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plan of Bristol written by and published by . This book was released on 1964 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
