Download or read book Study of Rare B Meson Decays Related to the CP Observable Sin 2 beta gamma at the BABAR Experiment written by Toyoko Jennifer Orimoto and published by . This book was released on 2006 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Rare B Meson Decays Related to the CPObservable Sin 2beta gamma at the BABAR Experiment written by and published by . This book was released on 2006 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study reports the observation of the decays B02!$*+\atop{s}$[pi]- and B02!(*)-K+ in a sample of 230 x 106 Y(4S) 2!B$\bar{B}$ events collected with the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring, located at the Stanford Linear Accelerator Center. The branching fractions [beta](B0 2!D$+\atop{S}$[pi]- ) = (1.3 ± 0.3 (stat) ± 0.2 (syst)) x 10-5, [beta](B0 2!D$+\atop{S}$K+) = (2.5 ± 0.4 (stat) ± 0.4 (syst)) x 10-5, [beta](B02!$*+\atop{s}$[pi]- ) = (2.8 ± 0.6 (stat) ± 0.5 (syst)) x 10-5, and [beta](B02!(*)-K+) = (2.0 ± 0.5 (stat) ± 0.4 (syst)) x 10-5 are measured. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively. This is a first observation of the decaysB+2!$*+\atop{s}$[pi]- and B02!(*)-K+. These results may potentially be useful in determining the CP asymmetry parameter sin(2[beta] + [gamma]) in the decays B02!$*+\atop{s}$[pi]-

Download or read book Study of Hadronic and Rare B Decays in BABAR written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from BaBar experiment for the measurement of inclusive and exclusive branching fractions of B mesons into final states containing J/[psi], [psi](2S) and [chi]c. The contributions of CP even and odd amplitudes in the decay B° 2!J/[psi]K*° are determined from an angular analysis. We report the measurements of the branching ratios B° 2!D* D*− and D* D*− K{sub S}°, and the study of exclusive two-body and quasi-two-body charmless decays. The branching fraction of the decay B° 2!K*°[gamma] has been determined and the corresponding CP asymmetry has been measured.

Download or read book Study of the Rare Decay B0 to Pi0 Pi0 at BaBar 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 operating at the PEP-II ee− collider is designed to study CP violation effects in the B-meson system. From May 1999 to June 2002 approximately 81 fb−1 of data have been collected at the [Upsilon](4S) resonance, containing (87.9 ± 1.4) Million BB pairs. From this data sample the branching fraction for the decay B° 2![pi]°[pi]° has been extracted using a multi-dimensional maximum likelihood technique. With an efficiency of 20.4%, we find 3614−1{sup +15+1} B° 2![pi]°[pi]° events and measure the branching fraction to be [Beta](B° 2![pi]°[pi]°) = (2.0{sub -0.8-0.2}{sup +0.9+0.3}) x 10−6 where the first error is statistical and the second systematic. The statistical significance is 3.1[sigma] and we report an upper limit of [Beta](B° 2![pi]°[pi]°)

Download or read book Studying B S Gamma at BABAR Using a Fully Inclusive Method written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The b [yields] s[gamma] decay represents a possible electromagnetic ''loop'' penguin decay of the B meson. This FCNC process is of high theoretical interest because various scenarios of new physics are expected to have contributions at the same (one loop) level as the Standard Model. The large sample of B[bar B] meson decays collected by the BaBar experiment makes a precision measurement of this rare decay possible. In conjunction with Standard Model predictions at the 10% level, it brings new physics effects into the realm of detection--or seriously constrains models that could predict them. A fully inclusive technique is presented to study the b [yields] s[gamma] transition as a function of photon energy, using 88.5 [+-] 1.0 x 10[sup 6] B[bar B] meson decays collected by the BaBar experiment in the years 2000 to 2002. The expected statistical and systematic uncertainties have been fully determined which enables first comparisons with theoretical predictions and other experimental results. It also lays the basis for the determination of the inclusive branching fraction [Beta](B [yields] X[sub s][gamma]) and the measurement of the photon energy spectrum.

Download or read book Study of Rare B Meson Decays Related to the CKM Angle Beta at BaBar written by and published by . This book was released on 2007 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of CP Violation Mixing and Lifetimes in B Mesons Decays with the BABAR Experiment at PEP II written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The BABAR detector, which operates at the SLAC PEP-II asymmetric ee−collider at energies near the [Upsilon](4S) resonance has collected about 23M B{bar B} pairs in year 2000. Based on this data sample, we present a first study of sin2[beta], with samples of B° 2!J/[psi] K{sub s}°, B° 2 K{sub s}° and B° 2!J/[psi] K{sub L}° decays. The measured value is sin2[beta] = 0.34 ± 0.20 (stat) ± 0.05 (syst). In addition, we present preliminary measurements of charged and neutral B meson lifetimes and B°{bar B}° oscillation frequency.

Download or read book Rare B Meson Decays With Omega Mesons written by Lei Zhang and published by . This book was released on 2006 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.

Download or read book CP Violation in B Decays and the BaBar Experiment written by and published by . This book was released on 2001 with total page 5 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−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° → J/[psi] K{sub S}°, B° → [psi](2S) K{sub S}° and B° → J/[psi] K{sub L}° 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°{bar B}° oscillation frequency.

Download or read book Rare Hadronic B Decays written by A. J. Bevan and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare hadronic B-meson decays allow us to study CP violation. The class of B-decays final states containing two vector mesons provides a rich set of angular correlation observables to study. This article reviews some of the recent experimental results from the BABAR and Belle collaborations.

Download or read book The Search for Rare Non hadronic B meson Decays with Final state Neutrinos Using the BaBar Detector written by Dana Lindemann and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis presents the searches for two rare B meson decays: the radiative leptonic decay B+ -> l+ nu gamma (l = e, mu) and the flavor-changing neutral current B -> K(*) nu nubar. These searches use the full dataset collected by the BaBar experiment, which corresponds to almost 500 million BB pairs. After fully reconstructing the hadronic decay of one of the B mesons in Upsilon(4S) -> BB decays, evidence of B+ -> l+ nu gamma or B -> K(*) nu nubar is looked for in the rest of the event. No significant evidence of either signal decay is observed. Model-independent branching-fraction upper limits are set at BR(B ->e nu gamma)17 x10 {-6}, BR(B -mu nu gamma)24 x10 {-6}, and BR(B -l nu gamma)15.6 x10 {-6}, all at the 90% confidence level. These are currently the most stringent published upper limits for B+ - l+ nu gamma. In addition, branching-fraction upper limits are set at BR(B -> K+ nu nubar)3.7 x10 {-5}, BR(B - K0 nu nubar)8.0 x10 {-5}, BR(B - K*+ nu nubar)11.5 x10 {-5}, and BR(B - K*0 nu nubar)9.2 x10 {-5}, all at the 90% confidence level. For additional sensitivity to New Physics contributions, partial B - K(*) nu nubar branching-fraction upper limits are also determined over the full kinematic range." --

Download or read book Rare And Radiative B Meson Decays From the BaBar Experiment written by J. Stelzer and published by . This book was released on 2006 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its start in 1999 the BABAR experiment has collected a vast amount of data. Electron-positron collisions at the energy of the {Upsilon}(4S) resonance have produced about 240 million coherent B{sup 0}{bar B}{sup 0} and B{sup +}B{sup -} pairs, opening the doors for exploration of rare B meson decays. An overview of the electroweak penguin physics program of BABAR is given, the analysis of two specific decays is presented in detail.

Download or read book Measurements of Branching Fraction and CP Violation in B Meson Rare Decays to Final States Containing Or Mesons in the BaBar Experiment at SLAC written by Alfio Lazzaro and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of B Meson Decays to Ppbarh Final States written by Tetiana B. Hryn'ova and published by . This book was released on 2006 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X{sub c{bar c}} = {eta}{sub c} or J/{psi}. In particular, we report on the evidence of the B {yields} {eta}{sub c}K*{sup +} decay and provide a measurement of the width of {eta}{sub c}.

Download or read book Search for the Rare Decay of a B Meson Into a Lambda Baryon Proton and Neutrino antineutrino Pair at the BABAR and Belle II Experiments written by Robert Seddon and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "We present two analyses of the rare B- -> Lambda pbar nu nubar decay. Within the Standard Model, the process B- -> Lambda pbar nu nubar is permitted but highly suppressed, with an expected branching fraction of (7.9 +/- 1.9) x 10^-7. This rarity makes it a sensitive probe for the existence of new physics, which may be discoverable in the form of a higher than predicted branching fraction.The first analysis is conducted on data collected at the BABAR experiment, which ran from 1999-2008. BABAR collected 433 fb^-1 of integrated luminosity at the Upsilon(4S) resonance; Upsilon(4S) decays almost exclusively into B-Bbar pairs, and this analysis uses hadronic tag reconstruction to fully reconstruct one of the B-mesons in this pair. The search for B- -> Lambda pbar nu nubar is then conducted among the decay products of the second, unreconstructed B-meson. Using both real data and Monte Carlo simulations, we develop and implement a signal selection that selects candidates conforming to the expected characteristics of B- -> Lambda pbar nu nubar decays. The result of the analysis is an upper limit on the branching fraction at the 90% confidence level of 3.02 x 10^-5. This is the world's first experimental result in the search for B- -> Lambda pbar nu nubar decays.The second analysis is conducted on Monte Carlo simulations of data that will be collected at Belle II, the world's only next-generation B-meson facility. Over its lifetime Belle II will collect 50 ab^-1 of data, approximately 100 times that of BABAR. This increase in data, along with more capable hardware and software, should allow Belle II to search for B- -> Lambda pbar nu nubar decays with greater sensitivity than BABAR. Using a simulated dataset equivalent in size to that used in our BABAR study, we employ Full Event Interpretation to fully reconstruct the decay of one B-meson in each B-Bbar pair, and conduct our signal selection in the remainder of the data. The result of the analysis is a predicted upper limit on the branching fraction at the 90% confidence level of 1.2 x 10^-4. A comparison of the Belle II and BABAR results highlights several areas where Belle II will need to improve in order to make best use of its projected dataset"--

Download or read book Study of B0 to D 0h0 Decay and Measurement Ofsin 2beta written by and published by . This book was released on 2007 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a measurement of a CP violating asymmetry in neutral B meson decays, B° yields D{sup *0}h°, where D{sup *0} is a charmed meson and h° is a light meson, performed on data collected by the BABAR experiment at the SLAC asymmetric-energy electron-positron collider PEP-II.

Download or read book Charmless Hadronic B Decays at Belle and BaBar written by and published by . This book was released on 2011 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: I report on recent measurements from the Belle and BABAR collaborations on the decay of the B meson to hadronic final states without a charm quark. The study of the branching fractions and angular distributions of B meson decays to hadronic final states without a charm quark probes the dynamics of both the weak and strong interactions, and plays an important role in understanding CP Violation (CPV) in the quark sector. CP Violation at the B factories is described graphically by a triangle with sides formed from the CKM matrix elements V{sub qd}V*{sub qb} (q = u, c, t) and internal angles [alpha], [beta] [gamma] (or [phi]2, [phi]1, [phi]3). Discrepancies in the measured values of the sides and angles could be an indication of New Physics beyond the Standard Model (SM) due to enhanced branching fractions or modified CP asymmetries. The experimental measurements of branching fractions, CP asymmetries, polarization and phases (both weak and strong) can be compared to theoretical models based on, for example, QCD factorization, SU(3) symmetry and Lattice QCD.