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.

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.

Leptonic Decays of the Charged B Meson

Leptonic Decays of the Charged B Meson PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

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Book Description
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)

Muon-flavored Pure Leptonic Decay of the Charged B Meson at the BABAR Experiment

Muon-flavored Pure Leptonic Decay of the Charged B Meson at the BABAR Experiment PDF Author: C. Jess Riedel
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Radiative and Leptonic B-meson Decays from the B-factories

Radiative and Leptonic B-meson Decays from the B-factories PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

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Book Description
Radiative and leptonic decays of B-mesons represent an excellent laboratory for the search for New Physics. I present here recent results on radiative and leptonic decays from the Belle and BABAR collaborations. Radiative penguin and leptonic B-meson decays are excellent probes for investigating the effects of New Physics. Although current measurements are in agreement with the Standard Model expectations, they are still quite useful for setting bounds on possible NP models. The B → X{sub s}[gamma] and B → [tau][nu] measurements, for example, put strong constraints on the mass of charged Higgs bosons in Type II two-Higgs double models. The B → X{sub s}[gamma] branching fraction measurements also constrain models with universal extra dimensions.

A Study of Purely Letonic Decays of the Charged B Meson

A Study of Purely Letonic Decays of the Charged B Meson PDF Author: Pablo Hopman
Publisher:
ISBN:
Category :
Languages : en
Pages : 364

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Fully Leptonic Decays of B Mesons

Fully Leptonic Decays of B Mesons PDF Author: Mark Joseph Lattery
Publisher:
ISBN:
Category :
Languages : en
Pages : 384

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Exclusive Semi-leptonic Decays of B Mesons

Exclusive Semi-leptonic Decays of B Mesons PDF Author: Christopher P. O'Grady
Publisher: Ann Arbor, Mich. : University Microfilms International
ISBN:
Category :
Languages : en
Pages : 210

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Book Description


B Decays

B Decays PDF Author: Sheldon Stone
Publisher: World Scientific
ISBN: 9789810218362
Category : Science
Languages : en
Pages : 676

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Book Description
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.

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

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 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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].

Leptonic Decays of Charged Pseudoscalar Mesons - 2015

Leptonic Decays of Charged Pseudoscalar Mesons - 2015 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We review the physics of purely leptonic decays of $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be used to test the unitarity of the first and second rows of the CKM matrix. Conversely, taking the CKM elements predicted by unitarity, one can infer "experimental" values for $f_P$ that can be compared with theory. These provide tests of lattice-QCD methods, provided new-physics contributions to leptonic decays are negligible at the current level of precision. This review is the basis of the article in the Particle Data Group's 2016 edition, updating the versions in Refs. [1-3].