Download or read book Study of B ulnu bar Decays on the Recoil of Fully Reconstructed B Mesons and Determination of verticalVub vertical written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: No abstract prepared.
Download or read book Study of B ulnu bar Decays on the Recoil of Fully Reconstructed B Mesons and Determination of written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Bbar to Xu L Nubar Decays in BBbar Events Tagged by a Fully Reconstructed B meson Decay and Determination of written by and published by . This book was released on 2012 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report measurements of partial branching fractions for inclusive charmless semileptonic B decays {bar B} → X{sub u}l{bar {nu}}, and the determination of the CKM matrix element.
Download or read book Measurement of the Relative Branching Fractions of Bbar to D D D L Nubar l Decays in Events with a Fully Reconstructed B Meson written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We determine the relative branching fractions of semileptonic B decays to charmed final states. The measurement is performed on the recoil from a fully reconstructed B meson in a sample of 362 million B{bar B} pairs collected at the [Upsilon](4S) resonance with the BABAR detector. A simultaneous fit to a set of discriminating variables is performed on a sample of {bar B} → DXl−{bar {nu}}{sub {ell}} decays to determine the contributions from the different channels.
Download or read book An Inclusive Measurement of the Branching Fraction for the B 602 s 222 Using the Recoil of Fully Reconstructed B Meson Decays written by Clare Louise Brown 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 Measurement of the Branching Fractions of Bbar D L Nubar l Decays in Events Tagged by a Fully Reconstructed B Meson written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the branching fractions of {bar B} 2!D** l−{bar {nu}}{sub l} decays based on 417 fb−1 of data collected at the [Upsilon](4S) resonance with the BABAR detector at the PEP-II ee− storage rings. Events are selected by fully reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D{sup (*)})-m(D{sup (*)}) is performed to extract the signal yields of the different D** states. We observe the {bar B} 2!D**{ell}−{bar {nu}}{sub {ell}} decay modes corresponding to the four D** states predicted by Heavy Quark Symmetry with a significance greater than six standard deviations including systematic uncertainties.
Download or read book Crippen wedi ei gondemnio i farw am lofruddio a darnio ei wraig a i chladdu yn seler ei dy written by and published by . This book was released on 18?? with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Inclusive Measurement of the Branching Fraction for the B u2192 s Using the Recoil of Fully Reconstructed B Meson Decays written by Clare Louise Brown and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Inclusive Measurement of the Branching Fraction for the B u2192 s Using the Recoil of Fully Reconstructed B Meson Decays written by Clare Louise Brown and published by . This book was released on 2005 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Inclusive Measurement of the Branching Fraction for the B u2192 s Using the Recoil of Fully Reconstructed B Meson Decays written by Clare Louise Brown and published by . This book was released on 2005 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Study of B Meson Decays with Excited Eta and Eta prime Mesons written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using 383 million B{bar B} pairs from the BABAR data sample, they report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to K{bar K}* or [eta][pi][pi] final states with mass in the range (1.2-1.8) GeV/c2. They observe a significant enhancement at the low K{bar K}* invariant mass which is interpreted as B 2K, find evidence for the decay B+ 2K+, and place upper limits on the decays B+ 2K+, B+ 2!f1(1285)K+, B+ 2!f1(1420)K+, and B+ 2K+.
Download or read book Search for Bbar to Lambda c X L Nu Decays in Events with a Fully Reconstructed B Meson written by and published by . This book was released on 2012 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for semileptonic B decays to the charmed baryon [Lambda]{sub c} based on 420 fb−1 of data collected at the [Upsilon](4S) resonance with the BABAR detector at the PEP-II e+e− storage rings. By fully reconstructing the recoiling B in a hadronic decay mode, we reduce non-B backgrounds and determine the flavor of the signal B. We statistically correct the flavor for the effect of the B° mixing. We obtain a 90% confidence level upper limit of [Beta]({bar B} 2![Lambda]{sub c}+ Xl− {bar [nu]}{sub l})/[Beta]({bar B} 2![Lambda]{sub c}+ X)
Download or read book Study of Exclusive Semileptonic B Meson Decays to Tau Leptons written by Michael A. Mazur and published by ProQuest. This book was released on 2007 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for four exclusive semileptonic decays B & rarr; D(*)tau -nutau in 209 fb -1 of data collected with the BABAR detector, corresponding to 232 million e+e - & rarr; Upsilon(4S) & rarr; B B events. We select events with a D (*) meson and a light lepton (e or mu) recoiling against a fully-reconstructed B meson. We perform a fit to the lepton spectrum and missing mass squared to discriminate signal events from backgrounds, predominantly B & rarr; D (*) & ell;-nu & ell; . A control sample of identified D** & ell;- nu & ell; events is included in the fit to estimate the background contribution from these decays. We measure B (B & rarr; Dtaunu) = (0.86+/-0.24+/-0.11+/-0.06)% and B (B & rarr; D*taunu) = (1.62+/-0.31+/-0.10+/-0.05)%, where the errors are statistical, systematic, and normalization-mode related, respectively, and where the results are expressed for the B0 lifetime.
Download or read book A MEASUREMENT OF THE LIFETIME AND MIXING FREQUENCY OF NEUTRAL B MESONS WITH SEMILEPTONIC DECAYS IN THE BABAR DETECTOR written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutral B meson, consisting of a b quark and an anti-d quark, can mix (oscillate) to its own anti-particle through second-order weak interactions. The measurement of the mixing frequency can constrain the quark mixing matrix in the Standard Model of particle physics. The PEP-II B-factory at the Stanford Linear Accelerator Center provides a very large data sample that enables us to make measurements with much higher precisions than previous measurements, and to probe physics beyond the Standard Model. The lifetime of the neutral B meson[tau][sub B0] and the B[sup 0]-[bar B][sup 0] mixing frequency[Delta]m[sub d] are measured with a sample of approximately 14,000 exclusively reconstructed B[sup 0][yields] D*[sup -][ell][sup+][nu][sub[ell]] signal events, selected from 23 million B[bar B] pairs recorded at the[Upsilon](4S)resonance with the BABAR detector at the asymmetric-energy e[sup+]e[sup -] collider, PEP-II. The decay position of the exclusively reconstructed B is determined by the charged tracks in the final state, and its b-quark flavor at the time of decay is known unambiguously from the charge of the lepton. The decay position of the other B is determined inclusively, and its b-quark flavor at the time of decay is determined (tagged) with the charge of tracks in the final state, where identified leptons or kaons give the most information. The decay time difference of two B mesons in the event is calculated from the distance between their decay vertices and the Lorentz boost of the center of mass. Additional samples of approximately 50,000 events are selected for studies of background events. The lifetime and mixing frequency, along with wrong-tag probabilities and the time-difference resolution function, are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in B decay times ([Delta]t), the calculated uncertainty on[Delta]t, the signal and background probabilities, and b-quark tagging for the other B meson. The results are[tau][sub B[sup 0]]= (1.523[sub -0.023][sup+0.024][+-] 0.022) ps and[Delta]m[sub d]= (0.492[+-] 0.018[+-] 0.013) ps[sup -1], where the first error is statistical and the second is systematic. The statistical correlation coefficient between[tau][sub B[sup 0]] and[Delta]m[sub d] is -0.22. This result is consistent with the current world average values, the total errors are comparable with other most-precise measurements.
Download or read book Leptonic Decays of the Charged B Meson written by and published by . This book was released on 2008 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the decay B+ 2!l+[nu] (= [tau], [mu], or e) in (458.9±5.1)×106 [Upsilon](4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B- 2!D0l -$\bar{v}$X) is selected, and in the recoil a search for B+ 2! +[nu]l signal is performed. The [tau] is identified in the following channels: [tau]+ 2!e+[nu]e$\bar{v}$[tau], [tau]+ 2![mu]+[nu][mu]$\bar{v}$[tau], [tau]+ 2![pi]+$\bar{v}$[tau], and [tau]+ 2![pi]+[pi]0$\bar{v}$[tau] . The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. We determine from the dataset a preliminary measurement of B(B+ 2![tau]+[nu][tau]) = (1.8 ± 0.8 ± 0.1) × 10-4, which excludes zero at 2.4[sigma], and fB = 255 ± 58 MeV. Combination with the hadronically tagged measurement yields B(B+ 2![tau]+[nu][tau]) = (1.8 ± 0.6) × 10-4. We also set preliminary limits on the branching fractions at B(B+ 2!e+[nu]e)
