The measured fraction of muon-like, single-track, atmospheric neutrino events over a 7.7 kton-yr ... more The measured fraction of muon-like, single-track, atmospheric neutrino events over a 7.7 kton-yr exposure of IMB is 0.36±O.02(stat)+O.O2(syst) as compared to an expectation of O.51:kO.Ol(stat):kO.O5(syst). No significant dependence of this fraction on zenith angle or momentum is seen. In addition, upward-going muons from higher energy atmospheric neutrino interactions are used to search for v, oscillations into v~ by comparing the measured rate with the expected rate from a conservative flux calculation. The ratio of upward-going muons which stop in the detector to those which exit is also used to search for deviations from the expected energy spectrum. No evidence for oscillations is found in either analysis. Finally, a search is made for an astrophysical component to the detected neutrino flux from both energetic point sources and gamma-ray bursts and also for a possible seasonal variation of the high energy neutrino flux due to atmospheric density changes. No evidence for any of these effects is found.
The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates... more The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates has been greeted with a great deal of justified excitement. The data reported so far depart by 4.3σ from the expected atmospheric neutrino background, which raises the obvious question: "Where in the Cosmos are these neutrinos coming from?" We review the many possibilities which have been explored in the literature to address this question, including origins at either Galactic or extragalactic celestial objects. For completeness, we also briefly discuss new physics processes which may either explain or be constrained by IceCube data.
Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernova... more Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernovae continuously, in real time, since the start of operations in 1996. The present work focuses on detecting more distant supernovae whose event rate may be too small to trigger in real time, but may be identified using an offline approach. The analysis of data collected from 2008 to 2018 found no evidence of distant supernovae bursts. This establishes an upper limit of 0.29 year −1 on the rate of core-collapse supernovae out to 100 kpc at 90% C.L.. For supernovae that fail to explode and collapse directly to black holes the limit reaches to 300 kpc.
The Antarctic Impulsive Transient Antenna (ANITA) experiment is being developed to search for ult... more The Antarctic Impulsive Transient Antenna (ANITA) experiment is being developed to search for ultra-highenergy (UHE) neutrino interactions (> 3 × 10 18 eV) in the Antarctic ice cap. A neutrino interaction in the ice will produce a radio pulse by the means of the Askaryan effect. The large radio transparency of ice allows for such a pulse to be recorded by a cluster of balloon-borne antennas. The details of the ANITA instrument, now in a construction phase, and the science we hope to achieve is discussed. In order to prepare for the main mission, we have flown ANITA-lite during the 2003/04 austral season. ANITA-lite consisted of two quad-ridge horn antennas and a prototype RF (radio frequency) triggering and recording system. Here we present the results of an impulsive RF background survey of Antarctica, as well as proof-of-principle gain, tracking, and timing calibrations conducted by observing solar radio emissions and calibration radio-pulses. A preliminary UHE neutrino flux limit based on ANITA-lite data is also presented.
From an exposure of 25.5 kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 el... more From an exposure of 25.5 kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 electron-like single-ring atmospheric neutrino interactions were detected with momentum p e > 100 MeV/c, p µ > 200 MeV/c, and with visible energy less than 1.33 GeV. Using a detailed Monte Carlo simulation, the ratio (µ/e) DAT A /(µ/e) MC was measured to be 0.61 ± 0.03(stat.) ± 0.05(sys.), consistent with previous results from the Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from theoretical models of atmospheric neutrino production.
S. Desai, Y. Ashie, S. Fukuda, Y. Fukuda, K. Ishihara, Y. Itow, Y. Koshio, A. Minamino, M. Miura,... more S. Desai, Y. Ashie, S. Fukuda, Y. Fukuda, K. Ishihara, Y. Itow, Y. Koshio, A. Minamino, M. Miura, S. Moriyama, M. Nakahata, T. Namba, R. Nambu, Y. Obayashi, N. Sakurai, M. Shiozawa, Y. Suzuki, H. Takeuchi, Y. Takeuchi, S. Yamada, M. Ishitsuka, T. Kajita, K. Kaneyuki, S. Nakayama, A. Okada, T. Ooyabu, C. Saji, M. Earl, E. Kearns, J.L. Stone, L.R. Sulak, C.W. Walter, W. Wang, M. Goldhaber, T. Barszczak, D. Casper, J.P. Cravens, W. Gajewski, W.R. Kropp, S. Mine, D.W. Liu, M.B. Smy, H.W. Sobel, C.W. Sterner, M.R. Vagins, K.S. Ganezer , J. Hill , W.E. Keig , J.Y. Kim, I.T. Lim, R.W. Ellsworth, S. Tasaka, G. Guillian , A. Kibayashi, J.G. Learned, S. Matsuno, D. Takemori, M.D. Messier, Y. Hayato, A. K. Ichikawa, T. Ishida, T. Ishii, T. Iwashita, J. Kameda, T. Kobayashi, T. Maruyama, K. Nakamura, K. Nitta, Y. Oyama, M. Sakuda, Y. Totsuka, A.T. Suzuki, M. Hasegawa, K. Hayashi, T. Inagaki, I. Kato, H. Maesaka, T. Morita, T. Nakaya, K. Nishikawa, T. Sasaki, S. Ueda, S. Yamamoto, T.J. Haines, S...
The Glashow resonance at E ν = 6.3 PeV is a measure of theν e content of the astrophysical neutri... more The Glashow resonance at E ν = 6.3 PeV is a measure of theν e content of the astrophysical neutrino flux. The fractionalν e content depends on the neutrino production model at the cosmic neutrino source, and the environment at the source. Thus, the strength of the Glashow resonance event rate is a potential window into astrophysical sources. We quantify the "Glashow resonometer" and comment on the significance that no Glashow events are observed in the IceCube three-year data.
There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does... more There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe either continuum events above 2 PeV, or the Standard Model Glashow-resonance events expected at 6.3 PeV. There are also no higher energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV. We postulate a simple scenario to terminate the neutrino spectrum that is Lorentz-invariance violating, but with a limiting neutrino velocity that is always smaller than the speed of light. If the limiting velocity of the neutrino applies also to its associated charged lepton, then a significant consequence is that the two-body decay modes of the charged pion are forbidden above two times the maximum neutrino energy, while the radiative decay modes are suppressed at higher energies. Such stabilized pions may serve as cosmic ray primaries.
Lunar neutrino physics. [AIP Conference Proceedings 202, 119 (1990)]. John G. Learned. Abstract. ... more Lunar neutrino physics. [AIP Conference Proceedings 202, 119 (1990)]. John G. Learned. Abstract. The possibilities of the use of the moon as a base for conducting neutrino physics are examined, exphasizing neutrino astronomy. ...
The scientific goals, design, capabilities, and status of the DUMAND II detector system are descr... more The scientific goals, design, capabilities, and status of the DUMAND II detector system are described. In June, 1989, the High Energy Physics Advisory Panel recommended support for construction of DUMAND II to the U.S. Department of Energy. Funding began in 1990, and prototype development for various detector subsystems is under way. Current plans include deployment of the shore cable, junction
The measured fraction of muon-like, single-track, atmospheric neutrino events over a 7.7 kton-yr ... more The measured fraction of muon-like, single-track, atmospheric neutrino events over a 7.7 kton-yr exposure of IMB is 0.36±O.02(stat)+O.O2(syst) as compared to an expectation of O.51:kO.Ol(stat):kO.O5(syst). No significant dependence of this fraction on zenith angle or momentum is seen. In addition, upward-going muons from higher energy atmospheric neutrino interactions are used to search for v, oscillations into v~ by comparing the measured rate with the expected rate from a conservative flux calculation. The ratio of upward-going muons which stop in the detector to those which exit is also used to search for deviations from the expected energy spectrum. No evidence for oscillations is found in either analysis. Finally, a search is made for an astrophysical component to the detected neutrino flux from both energetic point sources and gamma-ray bursts and also for a possible seasonal variation of the high energy neutrino flux due to atmospheric density changes. No evidence for any of these effects is found.
The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates... more The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates has been greeted with a great deal of justified excitement. The data reported so far depart by 4.3σ from the expected atmospheric neutrino background, which raises the obvious question: "Where in the Cosmos are these neutrinos coming from?" We review the many possibilities which have been explored in the literature to address this question, including origins at either Galactic or extragalactic celestial objects. For completeness, we also briefly discuss new physics processes which may either explain or be constrained by IceCube data.
Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernova... more Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernovae continuously, in real time, since the start of operations in 1996. The present work focuses on detecting more distant supernovae whose event rate may be too small to trigger in real time, but may be identified using an offline approach. The analysis of data collected from 2008 to 2018 found no evidence of distant supernovae bursts. This establishes an upper limit of 0.29 year −1 on the rate of core-collapse supernovae out to 100 kpc at 90% C.L.. For supernovae that fail to explode and collapse directly to black holes the limit reaches to 300 kpc.
The Antarctic Impulsive Transient Antenna (ANITA) experiment is being developed to search for ult... more The Antarctic Impulsive Transient Antenna (ANITA) experiment is being developed to search for ultra-highenergy (UHE) neutrino interactions (> 3 × 10 18 eV) in the Antarctic ice cap. A neutrino interaction in the ice will produce a radio pulse by the means of the Askaryan effect. The large radio transparency of ice allows for such a pulse to be recorded by a cluster of balloon-borne antennas. The details of the ANITA instrument, now in a construction phase, and the science we hope to achieve is discussed. In order to prepare for the main mission, we have flown ANITA-lite during the 2003/04 austral season. ANITA-lite consisted of two quad-ridge horn antennas and a prototype RF (radio frequency) triggering and recording system. Here we present the results of an impulsive RF background survey of Antarctica, as well as proof-of-principle gain, tracking, and timing calibrations conducted by observing solar radio emissions and calibration radio-pulses. A preliminary UHE neutrino flux limit based on ANITA-lite data is also presented.
From an exposure of 25.5 kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 el... more From an exposure of 25.5 kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 electron-like single-ring atmospheric neutrino interactions were detected with momentum p e > 100 MeV/c, p µ > 200 MeV/c, and with visible energy less than 1.33 GeV. Using a detailed Monte Carlo simulation, the ratio (µ/e) DAT A /(µ/e) MC was measured to be 0.61 ± 0.03(stat.) ± 0.05(sys.), consistent with previous results from the Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from theoretical models of atmospheric neutrino production.
S. Desai, Y. Ashie, S. Fukuda, Y. Fukuda, K. Ishihara, Y. Itow, Y. Koshio, A. Minamino, M. Miura,... more S. Desai, Y. Ashie, S. Fukuda, Y. Fukuda, K. Ishihara, Y. Itow, Y. Koshio, A. Minamino, M. Miura, S. Moriyama, M. Nakahata, T. Namba, R. Nambu, Y. Obayashi, N. Sakurai, M. Shiozawa, Y. Suzuki, H. Takeuchi, Y. Takeuchi, S. Yamada, M. Ishitsuka, T. Kajita, K. Kaneyuki, S. Nakayama, A. Okada, T. Ooyabu, C. Saji, M. Earl, E. Kearns, J.L. Stone, L.R. Sulak, C.W. Walter, W. Wang, M. Goldhaber, T. Barszczak, D. Casper, J.P. Cravens, W. Gajewski, W.R. Kropp, S. Mine, D.W. Liu, M.B. Smy, H.W. Sobel, C.W. Sterner, M.R. Vagins, K.S. Ganezer , J. Hill , W.E. Keig , J.Y. Kim, I.T. Lim, R.W. Ellsworth, S. Tasaka, G. Guillian , A. Kibayashi, J.G. Learned, S. Matsuno, D. Takemori, M.D. Messier, Y. Hayato, A. K. Ichikawa, T. Ishida, T. Ishii, T. Iwashita, J. Kameda, T. Kobayashi, T. Maruyama, K. Nakamura, K. Nitta, Y. Oyama, M. Sakuda, Y. Totsuka, A.T. Suzuki, M. Hasegawa, K. Hayashi, T. Inagaki, I. Kato, H. Maesaka, T. Morita, T. Nakaya, K. Nishikawa, T. Sasaki, S. Ueda, S. Yamamoto, T.J. Haines, S...
The Glashow resonance at E ν = 6.3 PeV is a measure of theν e content of the astrophysical neutri... more The Glashow resonance at E ν = 6.3 PeV is a measure of theν e content of the astrophysical neutrino flux. The fractionalν e content depends on the neutrino production model at the cosmic neutrino source, and the environment at the source. Thus, the strength of the Glashow resonance event rate is a potential window into astrophysical sources. We quantify the "Glashow resonometer" and comment on the significance that no Glashow events are observed in the IceCube three-year data.
There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does... more There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe either continuum events above 2 PeV, or the Standard Model Glashow-resonance events expected at 6.3 PeV. There are also no higher energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV. We postulate a simple scenario to terminate the neutrino spectrum that is Lorentz-invariance violating, but with a limiting neutrino velocity that is always smaller than the speed of light. If the limiting velocity of the neutrino applies also to its associated charged lepton, then a significant consequence is that the two-body decay modes of the charged pion are forbidden above two times the maximum neutrino energy, while the radiative decay modes are suppressed at higher energies. Such stabilized pions may serve as cosmic ray primaries.
Lunar neutrino physics. [AIP Conference Proceedings 202, 119 (1990)]. John G. Learned. Abstract. ... more Lunar neutrino physics. [AIP Conference Proceedings 202, 119 (1990)]. John G. Learned. Abstract. The possibilities of the use of the moon as a base for conducting neutrino physics are examined, exphasizing neutrino astronomy. ...
The scientific goals, design, capabilities, and status of the DUMAND II detector system are descr... more The scientific goals, design, capabilities, and status of the DUMAND II detector system are described. In June, 1989, the High Energy Physics Advisory Panel recommended support for construction of DUMAND II to the U.S. Department of Energy. Funding began in 1990, and prototype development for various detector subsystems is under way. Current plans include deployment of the shore cable, junction
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Papers by J. Learned