Precision Measurement of the Tau Lepton Mass and the Mass Difference of the Positively and Negatively Charged Tau Leptons at BaBar PDF Download

Author: Parker Lund
Publisher:
ISBN:
Category :
Languages : en
Pages : 386

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

View

Book Description
The authors present the result of a precision measurement of the mass of the? lepton, M{sub?}, based on 423 fb−1 of data recorded at the?(4S) resonance with the BABAR detector. Using a pseudomass endpoint method, they determine the mass to be 1776.68 ± 0.12(stat) ± 0.41(syst) MeV. They also measure the mass difference between the? and {tau}−, and obtain (M{sub {tau}+} - M{sub {tau}−})/M{sub AVG}{sup {tau}} = ( -3.4 ± 1.3(stat) ± 0.3(syst)) x 10−4, where M{sub AVG}{sup {tau}} is the average value of M{sub {tau}+} and M{sub {tau}−}.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 293

View

Book Description
Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a centre-of-mass energy near 10.58 GeV, the branching fractions B([tau]- 2![pi]-[pi]-[pi]+[nu][tau]) =(8.83±0.01±0.13)%, B([tau]- 2!K-[pi]-[pi]+[nu][tau]) =(0.273± 0.002 ± 0.009)%, B([tau]- 2!K-[pi]-K+[nu][tau]) =(0.1346 ± 0.0010 ± 0.0036)%, and B([tau]- 2!K-K-K+[nu][tau]) =(1.58 ± 0.13 ± 0.12) × 10-5 are measured where the uncertainties are statistical and systematic, respectively. The invariant mass distribution for the [tau]- 2![pi]-[pi]-[pi]+[nu][tau], [tau]- 2!K-[pi]-[pi]+[nu][tau], [tau]- 2!K-[pi]-K+[nu][tau] and [tau]- 2!K-K-K+[nu][tau] decays are unfolded to correct for detector effects. A measurement of B([tau]- 2![phi][pi]-[nu][tau]) =(3.42±0.55±0.25)×10-5, a measurement of B([tau]- 2![phi]K-[nu][tau]) =(3.39±0.20±0.28)× 10-5 and an upper limit on B([tau]- 2!K-K-K+[nu][tau] [ex.[phi]]) d"2.5 × 10-6@90%CL are determined from a binned maximum likelihood fit of the [tau]- 2!K-[pi]-K+[nu][tau] and [tau]- 2!K-K-K+[nu][tau] K+K- invariant mass distributions. The branching ratio B([tau]-2!-[nu][tau])/ B([tau]-2!pi]-[nu][tau]) is measured to be (6.531±0.056±0.093)×10-2 from which.

Author: Sterling Gray Watson
Publisher:
ISBN:
Category : Leptons (Nuclear physics)
Languages : en
Pages : 286

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

View

Book Description
Selected results from? analyses performed using the BABAR detector at the SLAC National Accelerator Laboratory are presented. A precise measurement of the? mass and the??− mass difference is undertaken using the hadronic decay mode?{sup ±} →?+?−?{sup ±}?{sub?}. In addition an investigation into the strange decay modes?− → K{sub S}°?−?°?{sub?} and?− → K{sub S}°?−?{sub?} is also presented, including a fit to the?− → K{sub S}°?−?{sub?} invariant mass spectrum. Precise values for M(K*(892)) and?(K*(892)) are obtained.

Author: Lawrence Aston Jones
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 296

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

View

Book Description
The BaBar collaboration has accumulated over 400 million [tau]-pairs which can be used to study charged leptonic and hadronic weak currents to unprecedented precision. This note presents results on lepton universality, measurements of.

Author: Achim Stahl
Publisher: Springer
ISBN: 9783662156537
Category : Science
Languages : en
Pages : 317

View

Book Description
The book reviews the current status of tau physics. It addresses the properties of the tau lepton and summarizes results achieved with tau leptons in the fields of precision tests of the Standard Model, investigations of the strong interaction and many searches for new physics beyond the scope of the Standard Model.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

View

Book Description
The mass of the [tau] lepton has been measured at the Beijing Electron Positron Collider using the Beijing Spectrometer. A search near threshold for e[sup +]e[sup [minus]] [yields] [tau][sup +][tau][sup [minus]] was performed. Candidate events were identified by requiring that one [tau] decay via [tau] [yields] e[nu][bar [nu]], and the other via [tau] [yields] [mu][nu][bar [nu]]. The mass value, obtained from a fit to the energy dependence of the [tau][sup +][tau][sup [minus]] cross section, is m[sub [tau]] = 1776.9[sub -0.5][sup +0.4] [plus minus] 0.2 MeV.

Author: A. Lusiani
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

View

Book Description
The mean lifetime of the tau lepton is measured from the decay length distribution of 3-prong tau decays from e{sup +}e{sup -} collisions at the {Upsilon}(4S) resonance. A data sample of 80.0 fb{sup -1} collected with the BABAR detector at the PEP-II B Factory is used for this measurement. The measured tau lifetime is: {tau}{sub {tau}} = 289.40 {+-} 0.91 (stat.) {+-} 0.90 (syst.) fs. All the results are preliminary.