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 Study of Exclusive Semileptonic B Meson Decays ToTau Leptons written by and published by . This book was released on 2007 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for four exclusive semileptonic decays B → D{sup (*)}[tau]−{bar [nu]}{sub [tau]} in 209 fb−1 of data collected with the BABAR detector, corresponding to 232 million e+e- → [Upsilon](4S) → B{bar B} events. We select events with a D{sup (*)} 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 → D{sup (*)}{tau}−{bar [nu]}{sub {tau}}. A control sample of identified D**l−{bar {nu}}{sub {ell}} events is included in the fit to estimate the background contribution from these decays. We measure [beta](B → D{sub {tau}{nu}}) = (0.86±0.24±0.11±0.06)% and [beta](B → D*{sub {tau}{nu}}) = (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 {bar B}° lifetime.
Download or read book Analysis of Inclusive Semileptonic B Meson Decays with Tau Lepton Final States at the Belle Experiment written by Jan Hasenbusch and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Leptonic Decays of the Charged B Meson written by Luke Andrew Corwin and published by . This book was released on 2008 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: We present a search for the decay of the charged B meson into a charged lepton and a neutrino 458.9 million Upsilon(4S) decays recorded with the Babar detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semileptonic B decay is selected, and in the recoil a search for the signal decay is performed. The tau lepton is identified in decays to an electron and two neutrinos; a muon and two neutrinos; a charged pion and a neutrino; or a charged pion, a neutral pion, and a neutrino. The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. We determine from the data set a preliminary measurement of the branching fraction a charged B decaying to a tau lepton and a neutrino = (1.8 " 0.8 " 0.1)E-4, which excludes zero at 2.4 standard deviations. We extract the B meson decay constant = 255 " 58 MeV. Combination with the hadronically tagged measurement yields (1.8 " 0.6)E-4. We also set preliminary limits on the branching fraction of charged B decaying to an electron and a neutrino at 7.7E-6 and the charged B decaying to a muon and a neutrino at 11E-6. The limits are at the 90% confidence level.
Download or read book B to Tau Leptonic and Semileptonic Decays written by and published by . This book was released on 2011 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decays of B mesons to states involving [tau] leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B → [tau][nu] and B → D{sup (*)}[tau][nu] is discussed, together with limits on new physics effects from current results. Leptonic and semileptonic decays of B mesons into states involving [tau] leptons remain experimentally challenging, but can prove a useful tool for constraining Standard Model parameters, and also offer to constrain the effects of any new physics that may exist including the presence of a charged Higgs boson.
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)
Download or read book Exclusive Semi leptonic Decays of B Mesons written by Christopher P. O'Grady and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 1993 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Inclusive Semileptonic B Meson Decays with Lepton Final States at the Belle Experiment written by Jan Hasenbusch and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Neutral B Meson Time Evolution Using Exclusively Reconstructed Semileptonic Decays written by T. Meyer and published by . This book was released on 2003 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model of particle physics describes the fundamental building blocks of the Universe and their basic interactions. The model naturally describes the time evolution of the basic particles, of which lifetime and mixing are two examples. The neutral B meson, consisting of a bottom quark and an oppositely charged down quark, enjoys a lifetime of about 1.5 ps and the special property of mixing with its antiparticle partner, the {bar B}{sup 0}. That is, due to second order weak interactions, the B{sup 0} meson can change into a {bar B}{sup 0} meson and back again as it evolves through time. The details of this behavior offer an opportunity to closely examine the Standard Model. In this dissertation, I report on a measurement of the lifetime and mixing frequency of the neutral B meson. Using the semileptonic decay channel B{sup 0} {yields} D*{sup -}{ell}{sup +}{bar {nu}}{sub {ell}}, we select more than 68,000 signal and background candidates from about 23 million B{bar B} pairs collected in 1999-2000 with the BABAR detector located at the Stanford Linear Accelerator Center. The other B in the event is reconstructed inclusively. By constructing a master probability density function that describes the distribution of decay time differences in the sample, we use a maximum likelihood technique to simultaneously extract the B{sup 0} lifetime and mixing parameters with precision comparable to the year 2000 world average. 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}. The statistical correlation coefficient between {tau}{sub B{sup 0}} and {Delta}m{sub d} is -0.22. I describe in detail several cutting-edge strategies this analysis uses to study these phenomena, laying important groundwork for the future. I also discuss several extensions of this work to include possible measurements of higher order parameters such as {Delta}{Lambda}{sub d}.
Download or read book Measurement of the Semileptonic Anti B to D Tau Anti Nu Tau Decays at 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: Semileptonic B meson decays into final states containing the [tau] lepton are of interesting as they provide information on the Standard Model as well as a window on new physics effects. We present results on {bar B} → D{sup (*)} [tau]{bar {nu}}{sub {tau}} decays where the second B in the event is fully reconstructed.
Download or read book A Study of Semileptonic B Decays And of Lepton Flavor Violating Tau Decays at BaBar written by and published by . This book was released on 2005 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of the semileptonic B decays at BABAR is presented. The results shown include measurements of the moments of hadronic-mass and electron-energy of the decay B → X{sub c}l[nu]; a determination of the.
Download or read book Preliminary Measurement of Time dependent B sub D sup 0 B sub D sup 0 Mixing Using Topology and Charge Selected Semi leptonic B Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The time dependence of B[sub d][sup 0]-B[sub d][sup 0] mixing has been measured using a sample of 150,000 hadronic Z[sup 0] decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p[sub t]) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. Vertex charge is used to enrich the selection of neutral over charged B mesons. This method results in a sample of 581 neutral decays with high charge purity. The B candidate is tagged at production with a combined tag that exploits the large polarized b forward-backward asymmetry in conjunction with the opposite hemisphere b jet charge. The final state is tagged by the sign of the high (p, p[sub t]) lepton. From their preliminary analysis the authors find a mass difference between the two B[sub d][sup 0] mass eigenstates of, [Delta]m[sub d]= 0.452[+-] 0.074(stat)[+-] 0.049(syst) ps[sup[minus]1].
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 Study of Exclusive Charmless Semileptonic Decays of the B Meson 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 Study of Exclusive Charmless Semileptonic Decays of the B Meson written by Amanda Jacqueline Weinstein and published by . This book was released on 2004 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lepton Mass Effects in Semi leptonic B meson Decays written by Jürgen G. Körner and published by . This book was released on 1989 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the B and B Lifetimes from Semileptonic Decays at SLD written by and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetimes of B and B° mesons have been measured using a sample of 150,000 hadronic Z° decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p{sub t}) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. This method results in a sample of 634 (584) charged (neutral) decays with high charge purity. A maximum likelihood fit finds: [tau]{sub B{sup +}} = 1.60{sub -0.11}{sup +0.12}(stat) ± 0.06(syst) ps, [tau]{sub B{sup 0}} = 1.55{sub -0.12}{sup +0.13}(stat) ± 0.09(syst) ps, and the ratio [tau]{sub B{sup +}}/[tau]{sub B{sup 0}} = 1.03{sub -0.13}{sup +0.15}(stat) ± 0.08(syst).
