Direct Measurement of the Neutral Weak Dipole Moments of the Tau Lepton

Direct Measurement of the Neutral Weak Dipole Moments of the Tau Lepton
Author:
Publisher:
Total Pages:
Release: 2001
Genre:
ISBN:

We present direct measurements of the neutral weak anomalous magnetic dipole moment, a[sub[tau]][sup w], and neutral weak electric dipole moment, d[sub[tau]][sup w], of the tau lepton. The dipole moments are measured by analyzing the decays of[tau] leptons produced in the annihilation of positrons and longitudinally polarized electrons on the Z boson resonance at the SLC. Using 6736 Z decays to[tau][sup+][tau][sup[minus]] pairs elected from our 1993-1998 data sample we obtain Re(a[sub[tau]][sup w])= (0.26[+-] 1.24) x 10[sup[minus]3], Im(a[sub[tau]][sup w])= ([minus]0.02[+-] 0.66) x 10[sup[minus]3], Re(d[sub[tau]][sup w])= (0.18[+-] 0.67) x 10[sup[minus]17] e[center-dot] cm, and Im(D[sub[tau]][sup w])= ([minus]0.26[+-] 0.37) x 10[sup[minus]17] e[center-dot] cm.

Search for Anomalous Couplings in the Decay of Polarized Z Bosons to [tau] Lepton Pairs

Search for Anomalous Couplings in the Decay of Polarized Z Bosons to [tau] Lepton Pairs
Author:
Publisher:
Total Pages: 223
Release: 1997
Genre:
ISBN:

Using a sample of 4,500 polarized Z decays to [tau] lepton pairs accumulated with the SLD detector at the SLAC Linear Collider (SLC) in 1993-95, a search has been made for anomalous couplings in the neutral current reaction e+e-→ [tau]+[tau]-. A measurement of the CP violating Weak Electric Dipole Moment (WEDM) and the CP conserving Weak Magnetic Dipole Moment (WMDM) of the [tau] lepton has been performed by considering the transverse spin polarization of [tau] leptons produced at the Z pole. Using a maximum likelihood technique, the observed [tau] decay spectra in the e, [mu], [pi], and [rho] decay channels are used to infer the net transverse polarization of the underlying tau leptons, and a fit for the anomalous dipole moments is performed. No evidence for these dipole movements is observed, and limits are placed on both the real and imaginary parts of the WEDM and WMDM.

Tau Lepton Physics - Proceedings Of The Second Workshop

Tau Lepton Physics - Proceedings Of The Second Workshop
Author: K K Gan
Publisher: World Scientific
Total Pages: 590
Release: 1993-04-08
Genre:
ISBN: 9814553433

The II International Workshop on Tau Lepton Physics was held in Ohio, USA in September 1992. Its purpose is to gather the experts on tau lepton physics to examine the current understanding of the tau lepton physics and to assess future prospects. A particular emphasis of the Workshop was a detailed examination of the '1-prong problem': the discrepancy between the inclusive measurement of one-charged-particle decay branching ratio and the sum of the exclusive decays. The Workshop also stimulated new ideas on tests of the Standard Model using the third generation lepton and assessed the future prospects of the lepton physics.

Measurement of the Tau Lepton Mass by the Beijing Spectrometer (BES) Collaboration

Measurement of the Tau Lepton Mass by the Beijing Spectrometer (BES) Collaboration
Author:
Publisher:
Total Pages: 11
Release: 1992
Genre:
ISBN:

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.