Author
T.P. McPharlin
Bio: T.P. McPharlin is an academic researcher from Stanford University. The author has contributed to research in topics: Positron & Muon. The author has an hindex of 3, co-authored 3 publications receiving 96 citations.
Papers
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TL;DR: An examination of 3.6 and 3.9 is the upper bound for the branching ratio with 90% confidence as mentioned in this paper, where the latter is an improved upper bound of 1.9.
Abstract: An examination of 3.6\ifmmode\times\else\texttimes\fi{}${10}^{10}$ ${\ensuremath{\mu}}^{+}$ decays yields an improved upper limit for the branching ratio $\frac{\ensuremath{\Gamma}({\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\gamma})}{\ensuremath{\Gamma}({\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{
u}}_{e}{\overline{\ensuremath{
u}}}_{\ensuremath{\mu}})}l1.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ with 90% confidence.
46 citations
TL;DR: In this article, a kinematically complete search for the muon decay was performed using a magnetic spectrometer outfitted with proportional chambers to measure the positron momentum vector and a large segmented NaI(Tl) array to determine the gamma-ray energy and impact point.
Abstract: This paper describes a kinematically complete search for the muon decay ..mu../sup +/..-->..e/sup +/..gamma... The experiment used a magnetic spectrometer outfitted with proportional chambers to measure the positron momentum vector and a large segmented NaI(Tl) array to determine the ..gamma..-ray energy and impact point. The positrons were mostly from normal muon decay while the ..gamma.. rays were mostly from internal and external bremsstrahlung. Approximately 3 x 10/sup 12/ muons were stopped in a 50-mg/cm/sup 2/ polyethylene target. The relative timing between the positron and the ..gamma.. ray was measured with a resolution of 1.9 ns full width at half maximum (FWHM) by the use of a plastic-scintillator hodoscope for the positron and by NaI(Tl) constant-fraction timing for the ..gamma.. ray. The positron energy resolution averaged over all data was 8.8% FWHM, and the ..gamma..-ray energy resolution was 8% FWHM, both at 52.8 MeV. When the ..gamma.. ray is assumed to originate at the same place in the target as the positron, the rms error in the measurement of the angle between the positron and ..gamma..-ray momentum vectors was 37 mrad. The acceptance of the apparatus for ..mu../sup +/..-->..e/sup +/..gamma.. events was (1.75 +- 0.04)%. A maximum-likelihood analysis established a 90%-confidencemore » upper limit for the branching ratio GAMMA(..mu../sup +/..-->..e/sup +/..gamma..)/GAMMA(..mu../sup +/..-->..e..nu nu..) of 1.7 x 10/sup -10/.« less
34 citations
TL;DR: An array of 45 NaI(Tl) crystals modules, each in 20 in. in length and hexagonal in cross section with six 3 in. sides, has been operated as a detector of 50 MeV γ-rays in a search for the decay μ + →e + γ as mentioned in this paper.
16 citations
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TL;DR: In this article, the results gathered here on simple Lie algebras have been selected with attention to the needs of unified model builders who study Yang-Mills theories based on simple, local symmetry groups that contain as a subgroup the SUw2 × Uw1 × SUc3 symmetry of the standard theory of electromagnetic, weak, and strong interactions.
1,251 citations
TL;DR: In this article, an economical model of generating finite and "calculable" Majorana neutrino masses is presented. But the model has a singly charged and a doubly charged singlet scalar which supply Majorana masses to the neutrinos at the two-loop level.
639 citations
KEK1
TL;DR: In this article, the current theoretical and experimental status of the field of muon decay and its potential to search for new physics beyond the standard model is reviewed, together with the recent up-to-date motivations of lepton flavor violation based on supersymmetric models.
Abstract: This article reviews the current theoretical and experimental status of the field of muon decay and its potential to search for new physics beyond the standard model. The importance of rare muon processes with lepton flavor violation is highly stressed, together with precision measurements of normal muon decay. Recent up-to-date motivations of lepton flavor violation based on supersymmetric models, in particular supersymmetric grand unified theories, are described along with other theoretical models. Future prospects of experiments and muon sources of high intensity for further progress in this field are also discussed.
604 citations
TL;DR: In this article, a detailed analysis of simplified models is presented for the correlation between the muon anomalous magnetic moment (g − 2 ) and the quest for lepton flavor violation are intimately correlated.
502 citations
TL;DR: In this article, the authors proposed an alternative to the Yanagida-Gell-Mann-Ramond-Slansky method of obtaining small neutrino masses in spite of normal Dirac mass terms in left-right symmetric theories.
326 citations