967 research outputs found

    Detector Depth Dependence of the High Energy Atmospheric Neutrino Flux

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    We note that detector depth can influence the decay path length available for the primary and secondary particles that are the source of atmospheric neutrinos. As a consequence there is a location dependent modulation to the neutrino flux, which could be as large as 5-10% in some directions

    History of "Anomalous" Atmospheric Neutrino Events: A First Person Account

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    The modern picture of the neutrino as a multiple mass highly mixed neutral particle has emerged over 40 years of study. Best known of the issues leading to this picture was the apparent loss of neutrinos coming from the sun. This article describes another piece of evidence that supports the picture; the substantial reduction of high energy muon type neutrinos observed in nature. For much of the 40 year period, before the modern picture emerged this observation was known as the "atmospheric neutrino anomaly", since as will be seen, these neutrinos originate in the Earth's atmosphere. This paper describes the discovery of the atmospheric neutrino anomaly. We explore the scientific context and motivations in the late 1970's from which this work emerged. The gradual awareness that the observations of atmospheric neutrinos were not as expected took place in the 1983-1986 period.Comment: 46 pages, 24 figures. To be published in Physics in Perspective Version 2 has a table of contents, a table of figures and the DOI added The final publication is available at Springer via http://dx.doi.org/10.1007/s00016-016-0185-

    Inconsistencies in Interpreting the Atmospheric Neutrino Anomaly

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    We note a discrepancy between the value of R expected on the basis of the muon neutrino angular distribution and the value actually observed. The energy independence of RR leads to a fine tuning problem. This may be indicative of some unaccounted for new physics.Comment: 3 pages, 5 figure

    Studies of Radiative Penguin B Decays at BaBar

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    We summarize results on a number of observations of penguin dominated radiative decays of the B meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment at PEP-II, the asymmetric B factory at SLAC.Comment: 3 pages, 5 figure

    Searching for Mass Concentrations with Precision Pulsar Timing

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    This papers searches for evidence of mass concentrations along the path of radio pulses in the PPTA2 survey data release. Radio pulse travel times are influenced via gravitational fields along the path from the source to the observer. Transient time delays in transit are a useful measure of the matter distribution along the path. Many pulsars have very well understood timing solutions with predicable arrival times and can be used to sample the mass variation. Changes in the source, observer and mass concentration positions produce changes in arrival times which can be significant for precision pulsar times. Twelve candidates are reported from this search.Comment: 8 pages, 15 figure
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