Author
L. E. Piilonen
Bio: L. E. Piilonen is an academic researcher from Los Alamos National Laboratory. The author has contributed to research in topics: Branching fraction & Particle decay. The author has an hindex of 4, co-authored 7 publications receiving 162 citations.
Topics: Branching fraction, Particle decay, Lepton, Muon, Quantum chromodynamics
Papers
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TL;DR: A search with the Crystal Box detector shows no evidence for the lepton-family-number-nonconserving decays, and upper limits for the branching ratios of GAMMA are provided.
Abstract: A search with the Crystal Box detector shows no evidence for the lepton-family-number-nonconserving decays ..mu -->..e..gamma.., ..mu -->..e..gamma gamma.., or ..mu -->..eee. The search provides upper limits for the branching ratios of GAMMA(..mu -->..e..gamma..)/GAMMA(..mu -->..evv-italic-bar) ..e..gamma gamma..)/GAMMA(..mu -->..evv-italic-bar) ..eee)/GAMMA(..mu -->..evv-italic-bar)<3.510/sup -11/ (90% C.L.). In addition, a limit for the emission of a light scalar or pseudoscalar boson in radiative muon decay is given.
122 citations
TL;DR: From a maximum-likelihood analysis of the Dalitz-plot distribution of 2364 coincident and random events, a unique value is obtained for ..gamma.., the ratio of the axial-vector to vector weak pion form factors, of 0.12.
Abstract: A new experiment studying radiative pion decay, ..pi../sup +/..-->..e/sup +/..nu../sub e/..gamma.., has been performed with the Crystal Box detector at the Clinton P. Anderson Meson Physics Facility. From a maximum-likelihood analysis of the Dalitz-plot distribution of 2364 coincident and random events, we obtain a unique value for ..gamma.., the ratio of the axial-vector to vector weak pion form factors, of 0.25 +- 0.12. The new world average is ..gamma.. -- 0.39 +- 0.06. .AE
29 citations
15 Feb 1988-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: An array of 49 NaI(Tl) modules each 20 inch in depth and 2.5 inch in cross section has been constructed and its properties, especially energy resolution, explored for positrons in the range 20 MeV − 18 GeV as mentioned in this paper.
Abstract: An array of 49 NaI(Tl) modules each 20 inch in depth and 2.5 inch × 2.5 inch in cross section has been constructed and its properties, especially energy resolution, explored for positrons in the range 20 MeV – 18 GeV. A subsequent much larger detector, the Crystal Box, has also been constructed from 396 modules of the same cross section, but mostly 12 inch in depth, and operated as a γ-ray and positron detector in a search for rare muon decays. The calibration procedure used for the Crystal Box and its characteristic resolutions in energy, impact point and time are described.
11 citations
TL;DR: In this paper, an experimental search for the spontaneous conversion of muonium to antimuonium was described, where a 10 MeV/c beam of average intensity was used to produce Muonium atoms in vacuum by charge capture.
Abstract: An experimental search for the spontaneous conversion of muonium to antimuonium is described. A 10 MeV/c ${\ensuremath{\mu}}^{+}$ beam of average intensity 3\ifmmode\times\else\texttimes\fi{}${10}^{5}$ ${\mathrm{s}}^{\ensuremath{-}1}$ was used to produce muonium atoms in vacuum by charge capture in a thin foil. The novel method applied here for detection of an antimuonium atom was a triple coincidence of two muonic x-ray photons from the atomic capture of its ${\ensuremath{\mu}}^{\ensuremath{-}}$ by a high-$Z$ target and a secondary electron ejected from the target upon the impact of the antimuonium atom. No antimuonium events were observed and the resulting 90% confidence level upper limit on the coupling constant leading to the conversion, ${G}_{M\overline{M}}$, is $6.9{G}_{F}$, where ${G}_{F}$ is the Fermi coupling constant.
4 citations
01 Dec 1992-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the MEGA experiment is used to search for the rare decay μ → eγ with a sensitivity of 10-13, where γ is the number of particles in the decays.
Abstract: One of the leading experimental projects at LAMPF has been the MEGA experiment. This is an experiment to search for the rare decay μ → eγ with a sensitivity of 10-13. A prime component of this proj ...
3 citations
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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
University of Maryland, College Park1, Autonomous University of Madrid2, University of Southampton3, Oklahoma State University–Stillwater4, University of Valencia5, Fermilab6, Northwestern University7, State University of Campinas8, University of Regina9, Stanford University10, Physical Research Laboratory11, Academia Sinica12, University of Pennsylvania13, Max Planck Society14, Amherst College15, Sapienza University of Rome16, Pennsylvania State University17, University of California, Berkeley18, CERN19, University of California, Los Angeles20, Bulgarian Academy of Sciences21, International School for Advanced Studies22, University of Manchester23, University of Florida24, Technische Universität München25, Yale University26, Virginia Tech27, Carnegie Mellon University28
TL;DR: A review of neutrino mass physics can be found in this paper, where the authors summarize what can be learned about neutrinos interactions as well as the nature of new physics beyond the Standard Model from various proposed Neutrino experiments.
Abstract: This paper is a review of the present status of neutrino mass physics, which grew out of an APS sponsored study of neutrinos in 2004. After a discussion of the present knowledge of neutrino masses and mixing and some popular ways to probe the new physics implied by recent data, it summarizes what can be learned about neutrino interactions as well as the nature of new physics beyond the Standard Model from the various proposed neutrino experiments. The intriguing possibility that neutrino mass physics may be at the heart of our understanding of a long standing puzzle of cosmology, i.e. the origin of matter?antimatter asymmetry is also discussed.
496 citations
TL;DR: In this paper, the flavour violating parameters of the low energy theory are derived in both SU(5) and SO(10) theories, and are used to calculate the rate for μ → eγ.
314 citations
TL;DR: In this paper, the SINDRUM II spectrometer has been used to perform a search for μ → e conversion in muonic atoms with the assumption of a giant resonance excitation of the Ca nucleaus.
288 citations