scispace - formally typeset

Posted Content

Predictions for energy distribution and polarization of the positron from the polarized muon decay

AbstractThe pure lepton decay of the polarized muon is considered, accounting for a new tensor interaction which is outside of the Michel local interactions. This interaction leads to new energy distribution and polarization of the final charged lepton. The presence of such a type of interaction is strongly required for the description of the latest experimental results on the weak radiative pion decay in the full kinematic region. Assuming quark–lepton universality, predictions for a deviation from the Standard Model are made using only one new parameter. They do not contradict the present experimental data and can be verified further in the on-going experiments at PSI and TRIUMF, at least to the level of 3 standard deviations.

Topics: Muon (61%), Lepton (58%), Pion (58%)

...read more

Content maybe subject to copyright    Report

Citations
More filters

Journal ArticleDOI
01 Jan 1980-Nature
Abstract: An Introduction to Quarks and Partons. By F.E. Close. Pp.481. (Academic: London, New York and San Francisco, 1979.) £26.40; $54.50.

253 citations


Posted Content
Abstract: The muon decay parameter delta characterizes momentum dependence of the parity-violating muon decay asymmetry. A new measurement of delta has been performed using the first physics data recorded by the TWIST experiment at TRIUMF. The obtained value, delta=0.74964+-0.00066(stat.)+-0.00112(syst.), is consistent with the Standard Model expectation delta=3/4. This is the first determination of delta performed using a blind analysis technique. Combined with other data, the measurement sets new model-independent limits on effective right-handed couplings of the muon. Improved limits on the product of another muon decay parameter, xi, and the muon polarization in pion decay, Pmu, are obtained in the form: 0.9960

6 citations


Cites methods from "Predictions for energy distribution..."

  • ...In [40] a prediction for the spectrum of positrons from muon decay is made based on the pion decay data....

    [...]


Posted Content
Abstract: It is known that the discrepancy in pion spectral functions extracted from positron-electron annihilation and tau decay leads to different predictions for the muon anomalous magnetic moment. We will show that this discrepancy effects also the extraction of the Cabibbo angle from the hadronic tau decays. The corrections to the tau branching fractions, corresponding to the presence of new centi-weak tensor interactions, allow us to extract the Cabibbo angle from tau decays in agreement with its other precision determinations. Thus a more precise value of |V_us|=0.2246 +/- 0.0012 is obtained and as a consequence f(0)=0.9645 +/- 0.0055 and F_K/F_pi=1.196 +/- 0.007.

2 citations


References
More filters

Book
23 Feb 1995
Abstract: Part 1 The standard electroweak model: structure of the standard model, P. Langacker renormalization of the standard model, W. Hollik predictions for e+e- processes, W. Holik radiative corrections to neutral current processes, W. Marciano. Part 2 Precision tests at e+e-colliders: e+e- annihilation below the Z pole, D. Haidt and R. Marshall Z-pole experiments, D. Schaile polarization in e+e- annihilation, A. Blondel the LEP II program, D. Treille future e+e- colliders at high energy, D. Burke. Part 3 The weak neutral current: the measurement of electroweak parameters from deep inelastic neutrino scattering, F. Perrier elastic neutrino-nucleon scattering, A.K. Mann neutrino-electron scattering, J. Panman atomic parity violation experiments, C. Wieman the theory of atomic parity violation, J. Sapirstein charged lepton-hadron asymmetries in target experiments, P. Souder precision electroweak tests at HERA, H. Spiesberger. Part 4 The weak charged current: the unitarity of the Quark mixing matrix, A. Sirlin beta decay, right-handed currents and the search for new physics, J. Deutsch precision measurements in muon and tau decays, W. Fetscher and H.-J. Gerber muon decay and beta decay beyond the standard model, P. Herczeg. Part 5 Precision tests at hadron colliders, E. Einsweiler. Part 6 Implications of precision experiments: tests of the standard model and searches for new physics, P. Langacker exotic fermions, D. London. Part 7 The future, M Luo.

279 citations


Journal ArticleDOI
01 Jan 1980-Nature
Abstract: An Introduction to Quarks and Partons. By F.E. Close. Pp.481. (Academic: London, New York and San Francisco, 1979.) £26.40; $54.50.

253 citations


Additional excerpts

  • ...ar X...

    [...]