B to Tau Leptonic and Semileptonic Decays

B to Tau Leptonic and Semileptonic Decays PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
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.

B to Tau Leptonic and Semileptonic Decays

B to Tau Leptonic and Semileptonic Decays PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
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.

Study of Exclusive Semileptonic B Meson Decays to Tau Leptons

Study of Exclusive Semileptonic B Meson Decays to Tau Leptons PDF Author: Michael A. Mazur
Publisher: ProQuest
ISBN: 9780549268611
Category :
Languages : en
Pages : 674

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Book Description
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.

A Study of Semileptonic B Decays And of Lepton Flavor Violating Tau Decays at BaBar

A Study of Semileptonic B Decays And of Lepton Flavor Violating Tau Decays at BaBar PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

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Book Description
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.

Measurement of the Semileptonic Decays B-]D Tau Nu and B-]D* Tau Nu

Measurement of the Semileptonic Decays B-]D Tau Nu and B-]D* Tau Nu PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 29

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Book Description
The authors present measurements of the semileptonic decays B− → D°?− {bar?}{sub?}, B− → D*°?−{bar {nu}}{sub?}, {bar B}° → D?− {bar {nu}}{sub?}, and {bar B}° → D*+?−{bar {nu}}{sub?}, which are sensitive to non-Standard Model amplitudes in certain scenarios. The data sample consists of 232 x 106?(4S) → B{bar B} decays collected with the BABAR detector at the PEP-II e+e− collider. They select events with a D or D* meson and a light lepton (l = e or?) recoiling against a fully reconstructed B meson. They perform a fit to the joint distribution of lepton momentum and missing mass squared to distinguish signal B → D{sup (*)}?− {bar {nu}}{sub?} ({tau}− → l− {bar {nu}}{sub l}{nu}{sub {tau}}) events from the backgrounds, predominantly B → D{sup (*)} l−{bar {nu}}{sub l}. They measure the branching-fraction ratios R(D) {triple_bond}?(B → D{tau}− {bar {nu}}{sub {tau}})/?(B → Dl− {bar {nu}}{sub {ell}}) and R(D*) {triple_bond}?(B → D*{tau}− {bar {nu}}{sub {tau}})/?(B → D* {ell}− {bar {nu}}{sub {ell}}) and, from a combined fit to B− and {bar B}° channels, obtain the results R(D) = (41.6 ± 11.7 ± 5.2)% and R(D*) = (29.7 ± 5.6 ± 1.8)%, where the uncertainties are statistical and systematic. Normalizing to measured B− → D{sup (*)0} {ell}− {bar {nu}}{sub {ell}} branching fractions, they obtain?(B → D{tau}− {bar {nu}}{sub {tau}}) = (0.86 ± 0.24 ± 0.11 ± 0.06)% and?(B → D*{tau}− {bar {nu}}{sub {tau}}) = (1.62 ± 0.31 ± 0.10 ± 0.05)%, where the additional third uncertainty is from the normalization mode. They also present, for the first time, distributions of the lepton momentum,

Analysis of Inclusive Semileptonic B Meson Decays with Tau Lepton Final States at the Belle Experiment

Analysis of Inclusive Semileptonic B Meson Decays with Tau Lepton Final States at the Belle Experiment PDF Author: Jan Hasenbusch
Publisher:
ISBN:
Category : Bosons
Languages : en
Pages :

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Book Description


Measurement of the Semileptonic Anti-B to D(*) Tau Anti-Nu/Tau Decays at BaBar

Measurement of the Semileptonic Anti-B to D(*) Tau Anti-Nu/Tau Decays at BaBar PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
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.

Study of Exclusive Semileptonic B Meson Decays ToTau Leptons

Study of Exclusive Semileptonic B Meson Decays ToTau Leptons PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 359

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Book Description
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.

A Search for the Rare Leptonic B- to Tau- Anti-neutrino Recoiling Against B+ to Decays to Anti-D*0 L+ Lepton-neutrino

A Search for the Rare Leptonic B- to Tau- Anti-neutrino Recoiling Against B+ to Decays to Anti-D*0 L+ Lepton-neutrino PDF Author: Mousumi Datta
Publisher:
ISBN:
Category :
Languages : en
Pages : 195

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Book Description
This thesis describes a search for the decay B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}} in 231.8 x 10{sup 6} {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{sup +} {yields} {bar D}*{sup 0} {ell}{sup +}{nu}{sub {ell}}) is selected, and in the recoil a search for B{sup -} {yields} {tau}{sup -} {bar {nu}}{sub {tau}} signal is performed in the following {tau} decay modes: {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {tau}{sup -} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{pi}{sup 0}{nu}{sub {tau}}, and {tau}{sup -} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}}. They find no evidence of signal, and they set a preliminary upper limit on the branching fraction of {beta}(B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}})

Semileptonic decays of B-mesons into tau ny tau

Semileptonic decays of B-mesons into tau ny tau PDF Author: Patrick Heiliger
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Book Description


Leptonic Decays of the Charged B Meson

Leptonic Decays of the Charged B Meson PDF Author: Luke Andrew Corwin
Publisher:
ISBN:
Category : B mesons
Languages : en
Pages : 148

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Book Description
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.