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47 results on '"T. Numao"'

1. Search for Lepton Number and Flavor Violation in K+ and π0 Decays

Author

L. Bician, J. Swallow, L. Di Lella, M. Misheva, H. O. Danielsson, G. Lehmann Miotto, Alessandro Lonardo, D. Soldi, D. Protopopescu, S. Martellotti, Luca Pontisso, Nicolas Lurkin, C. Graham, M. B. Brunetti, Claudio Santoni, V. Falaleev, A. Conovaloff, L. Federici, M. Vormstein, Babette Döbrich, A. M. Bragadireanu, K. Massri, B. Angelucci, A. Filippi, A. I. Zinchenko, L. Iacobuzio, E. B. Holzer, A. Salamon, G. Khoriauli, B. Wrona, C. J. Parkinson, F. Brizioli, Cristina Biino, E. Imbergamo, M. Moulson, S. Movchan, C. Lazzeroni, F. Ambrosino, T. Capussela, A. Gianoli, Y. Petrov, L. Fulton, D. Baigarashev, R. Fantechi, Rainer Wanke, C. Cerri, Mauro Piccini, Georgi P. Georgiev, Roberto Guida, Viacheslav Duk, Paul Laycock, E. Minucci, F. Duval, P. Rubin, Roberto Ammendola, Karol Kampf, S. Trilov, P. Lubrano, M. Sozzi, Paolo Massarotti, T. Numao, Fabrizio Petrucci, Emilio Leonardi, A. Baeva, Paolo Valente, Tomáš Husek, J. L. Fu, Leander Litov, I. Polenkevich, R. Page, V. Fascianelli, M. Perrin-Terrin, V. Palladino, P. F. Dalpiaz, Ilaria Neri, Vincenzo Bonaiuto, A. Fucci, N. Doble, F. Hahn, T. Enik, Douglas Bryman, Sergei Fedotov, N. De Simone, R. Marchevski, E. Gamberini, E. Lari, Mauro Raggi, D. T. Madigozhin, Antonino Sergi, Yu. Potrebenikov, M. Koval, G. Lamanna, Vladimir Ryjov, Giuseppe Latino, D. Coward, G. Saracino, L. Gatignon, A. Korotkova, M. Medvedeva, Giuseppe Ruggiero, M. Corvino, P. Petrov, Dave Britton, N. Estrada-Tristan, A. Mapelli, Evgueni Goudzovski, Yu.A. Kudenko, Jürgen Engelfried, S. Giudici, F. Bucci, G. D'Agostini, Vladimir Kekelidze, E. Iacopini, Matteo Lupi, D. Emelyanov, A. Sturgess, J. B. Dainton, S. Venditti, E. Menichetti, M. Pepe, A. Khotyantsev, F. Costantini, A. Ceccucci, B. Checcucci, R. W. L. Jones, G. Anzivino, Andrea Biagioni, R. Volpe, B. Jenninger, N. A. Molokanova, Andrea Bizzeti, O. Hutanu, Mattia Barbanera, M. Fiorini, M. Napolitano, S. Ghinescu, J. Henshaw, A. Shaikhiev, Francesco Gonnella, A. Antonelli, E. Maurice, Mario Giorgi, Jacopo Pinzino, V. Kurochka, Tomas Blazek, V. Kozhuharov, L. Peruzzo, M. Zamkovsky, D. Di Filippo, A. Cotta Ramusino, B. Bloch-Devaux, J. Jerhot, F. Newson, Roberta Arcidiacono, V. Cerny, S. Shkarovskiy, F. Marchetto, V. Obraztsov, Piero Vicini, S. Schuchmann, Helen F Heath, V. E. Semenov, E. Gushchin, P. Lichard, Z. Kucerova, H. D. Wahl, E. Pedreschi, A. Romano, Fausto Sargeni, M. Mirra, A P Ostankov, Matthew Noy, M. Boretto, E. Cortina Gil, Roberto Piandani, P. Cenci, Johannes Bernhard, J. Kunze, G. Lanfranchi, A. Parenti, F. Spinella, R. Lollini, B. Velghe, J. Carmignani, Ernesto Migliore, M. Lenti, S. Padolski, J. R. Fry, V. Sugonyaev, T. Bache, R. Aliberti, A. Norton, D. Lomidze, D. E. Hutchcroft, O. Yushchenko, V. Kurshetsov, S. Kholodenko, Tommaso Spadaro, P. Cooper, A. Mefodev, I. Mannelli, and A. Kleimenova

Subjects
Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, High Energy Physics::Phenomenology, Flavour, General Physics and Astronomy, 01 natural sciences, Lepton number, 0103 physical sciences, Pi, High Energy Physics::Experiment, 010306 general physics, Lepton
Abstract

Searches for the lepton number violating $K^{+} \rightarrow \pi^{-} \mu^{+} e^{+}$ decay and the lepton flavour violating $K^{+} \rightarrow \pi^{+} \mu^{-} e^{+}$ and $\pi^{0} \rightarrow \mu^{-} e^{+}$ decays are reported using data collected by the NA62 experiment at CERN in $2017$-$2018$. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: $\mathcal{B}(K^{+}\rightarrow\pi^{-}\mu^{+}e^{+})

Published
2021

2. Search for three body pion decays π+→l+νX

Author

S. Cuen-Rochin, M. Blecher, D. Vavilov, Song Chen, Masaharu Aoki, D. Protopopescu, Y. Igarashi, L. S. Littenberg, P. Gumplinger, A. Sher, Luca Doria, C. Malbrunot, R. E. Mischke, T. Sullivan, Shintaro Ito, D. Vom Bruch, T. Numao, Dave Britton, Alexis A. Aguilar-Arevalo, S. H. Kettell, Douglas Bryman, J. R. Comfort, Leonid Kurchaninov, and Ahmed Hussein

Subjects
Physics, Crystallography, Pion, 010308 nuclear & particles physics, Branching fraction, Full data, High Energy Physics::Phenomenology, 0103 physical sciences, 010306 general physics, Coupling (probability), 01 natural sciences, Boson
Abstract

The three body pion decays π+→l+νX(l=e,μ), where X is a weakly interacting neutral boson, were searched for using the full data set from the PIENU experiment. An improved limit on Γ(π+→e+νX)/Γ(π+→μ+νμ) in the mass range 0

Published
2021

3. Search for the rare decays π+→μ+νμνν¯ and π+→e+νeνν¯

Author

P. Gumplinger, Leonid Kurchaninov, D. Vavilov, Douglas Bryman, Chloé Malbrunot, D. Protopopescu, Ahmed Hussein, M. Blecher, L. S. Littenberg, A. Sher, Song Chen, J. R. Comfort, T. Sullivan, S. Cuen-Rochin, D. Kalashnikov, Masato Aoki, T. Numao, R. E. Mischke, Alexis A. Aguilar-Arevalo, S. H. Kettell, Dave Britton, D. Gorbunov, Shintaro Ito, Y. Igarashi, L. Doria, and D. Vom Bruch

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Atomic physics, 010306 general physics, 01 natural sciences
Published
2020

4. Improved search for heavy neutrinos in the decay π→eν

Author

L. S. Littenberg, Song Chen, Douglas Bryman, P. Gumplinger, S. H. Kettell, R. E. Mischke, D. Protopopescu, Ahmed Hussein, Y. Igarashi, J. R. Comfort, C. Malbrunot, Alexis A. Aguilar-Arevalo, D. Vom Bruch, S. Ito, D. Vavilov, Leonid Kurchaninov, M. Blecher, Masaharu Aoki, A. Sher, Luca Doria, T. Sullivan, T. Numao, Dave Britton, and S. Cuen-Rochin

Subjects
Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Spectrum (functional analysis), Pontecorvo–Maki–Nakagawa–Sakata matrix, 01 natural sciences, Spectral line, Positron energy, Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, Neutrino, 010306 general physics, Order of magnitude
Abstract

A search for massive neutrinos has been made in the decay π+→e+ν. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (π→e+νh). Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60–135 MeV/c2 were set and are an order of magnitude improvement over previous results.

Published
2018

5. Search for the rare decayK+→μ+νν¯ν

Author

Yoichi Tamagawa, A. Artamonov, M. Miyajima, J. Hu, Y. Yoshimura, O. V. Mineev, K. Mizouchi, George Redlinger, M. V. Diwan, A. N. Khotjantsev, Yu. G. Kudenko, R. Tschirhart, Takashi Nomura, A. Konaka, T. Fujiwara, Norihito Muramatsu, I-H. Chiang, A. Shaikhiev, P. S. Cooper, R. Poutissou, S. Sugimoto, D. V. Vavilov, D. I. Patalakha, A. O. Izmaylov, L. G. Landsberg, Masaaki Kobayashi, S. Kabe, Ewart W. Blackmore, T. Sato, L. S. Littenberg, I. A. Christidi, T. Sekiguchi, K. Omata, S. H. Kettell, V. Obraztsov, T. Tsunemi, J. Ives, T. Numao, Hanyu Wei, M. M. Khabibullin, J. A. Macdonald, Masaharu Nomachi, B. Bassalleck, Tamaki Yoshioka, B. Viren, Song Chen, N. V. Yershov, B. Lewis, T. Nakano, D. E. Jaffe, K. K. Li, Douglas Bryman, J. Mildenberger, R. C. Strand, T. K. Komatsubara, James Frank, P. Kitching, B. Bhuyan, T. Shinkawa, and Zhe Wang

Subjects
Physics, Particle physics, Muon, 010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, National laboratory, 01 natural sciences
Abstract

Evidence of the ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\nu}$ decay was searched for using E949 (Brookhaven National Laboratory, USA) experimental data with an exposure of $1.70\ifmmode\times\else\texttimes\fi{}1{0}^{12}$ stopped kaons. The data sample is dominated by the background process ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\gamma}$. An upper limit on the decay rate $\mathrm{\ensuremath{\Gamma}}({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\nu})l2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\mathrm{\ensuremath{\Gamma}}({K}^{+}\ensuremath{\rightarrow}\text{all})$ at 90% confidence level was set assuming the standard model muon spectrum. The data are presented in such a way as to allow calculation of rates for any assumed ${\ensuremath{\mu}}^{+}$ spectrum.

Published
2016

6. Improved Measurement of theπ→eνBranching Ratio

Author

D. Vavilov, T. Numao, M. Ding, Masaharu Aoki, Dave Britton, C. Malbrunot, Ahmed Hussein, Koji Yamada, L. S. Littenberg, T. Sullivan, S. Cuen-Rochin, S. Ito, Douglas Bryman, R. E. Mischke, Y. Igarashi, P. Gumplinger, A. Sher, D. Vom Bruch, Luca Doria, Leonid Kurchaninov, J. R. Comfort, Song Chen, S. H. Kettell, M. Blecher, D. Protopopescu, and Alexis A. Aguilar-Arevalo

Subjects
Physics, Crystallography, Branching fraction, General Physics and Astronomy, Statistical physics
Abstract

A new measurement of the branching ratio R_{e/μ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→μ^{+}ν+π^{+}→μ^{+}νγ) resulted in R_{e/μ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.

Published
2015

7. Search for heavy neutrinos inK+→μ+νHdecays

Author

L. S. Littenberg, P. S. Cooper, I. A. Christidi, R. Poutissou, K. Mizouchi, A. Artamonov, R. Tschirhart, T. Sato, J. Hu, M. Miyajima, T. Sekiguchi, Song Chen, Zhe Wang, O. V. Mineev, Tamaki Yoshioka, I. H. Chiang, N. V. Yershov, M. V. Diwan, Norihito Muramatsu, S. H. Kettell, D. V. Vavilov, A. N. Khotjantsev, Yoichi Tamagawa, Y. Yoshimura, P. Kitching, J. Ives, T. Numao, Yu. G. Kudenko, B. Bhuyan, J. A. Macdonald, B. Bassalleck, Takashi Nomura, Ewart W. Blackmore, L. G. Landsberg, A. Shaikhiev, A. Konaka, J. Mildenberger, R. C. Strand, T. Fujiwara, Masaharu Nomachi, V. Obraztsov, T. K. Komatsubara, K. K. Li, B. Viren, M. M. Khabibullin, Douglas Bryman, B. Lewis, T. Nakano, S. Kabe, D. E. Jaffe, D. I. Patalakha, James Frank, Masaaki Kobayashi, T. Shinkawa, Hanyu Wei, S. Sugimoto, A. O. Izmaylov, K. Omata, T. Tsunemi, and George Redlinger

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Muon, 010308 nuclear & particles physics, 0103 physical sciences, Pontecorvo–Maki–Nakagawa–Sakata matrix, Radiative transfer, Heavy neutrino, Neutrino, 010306 general physics, 01 natural sciences
Abstract

Evidence of a heavy neutrino, ν H , in the K + → μ + ν H decays was sought using the E949 experimental data with an exposure of 1.70 × 1 0 12 stopped kaons. With the major background from the radiative K + → μ + ν μ γ decay understood and suppressed, upper limits (90% C.L.) on the neutrino mixing matrix element between the muon and heavy neutrinos, | U μ H | 2 , were set at the level of 1 0 - 7 to 1 0 - 9 for the heavy neutrino mass region 175 to 300 MeV / c 2 .

Published
2015

8. Measurement of Direct Photon Emission inK+→π+π0γDecay

Author

M. S. Atiya, J. M. Poutissou, George Redlinger, A. Konaka, L. S. Littenberg, M. Kuriki, S. H. Kettell, T. Inagaki, T. Shinkawa, R. A. McPherson, S. S. Adler, M. Aoki, F. C. Shoemaker, K. K. Li, Douglas Bryman, R. Poutissou, J. R. Stone, Y. Yoshimura, T. Numao, C. Witzig, S. Sugimoto, J. S. Haggerty, R. Soluk, J. A. Macdonald, M. V. Diwan, M. M. Ito, Ewart W. Blackmore, P. D. Meyers, Norihito Muramatsu, T. Nakano, M. Ardebili, Y. Kuno, Motoki Kobayashi, Y. Kishi, S. Kabe, T. Sato, M. R. Convery, P. C. Bergbusch, I-Hung Chiang, T. F. Kycia, James Frank, J. Mildenberger, R. C. Strand, T. K. Komatsubara, and P. Kitching

Subjects
Physics, Meson, Branching fraction, Hadron, Bremsstrahlung, General Physics and Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinetic energy, Electromagnetic radiation, Nuclear physics, Particle decay, Pion, High Energy Physics::Experiment, Atomic physics
Abstract

We have performed a measurement of the K + !� + � 0 decay and have observed 2×10 4 events. The best fit to the decay spectrum gives a branching ratio for direct photon emission of (4.7 ± 0.8 ± 0.3) × 10 6 in the � + kinetic energy region of 55 to 90 MeV and requires no component due to interference with inner bremsstrahlung.

Published
2000

9. Measurement of Structure-Dependent K+→μ+νμγ Decay

Author

Y. Kishi, S. S. Adler, A. Stevens, M. Kuriki, P. C. Bergbusch, George Redlinger, M. S. Atiya, T. Sato, S. H. Kettell, I-Hung Chiang, M. Aoki, J. R. Stone, J. Mildenberger, F. C. Shoemaker, R. C. Strand, T. K. Komatsubara, T. Numao, J. A. Macdonald, K. K. Li, S. Sugimoto, M. R. Convery, P. Kitching, R. A. McPherson, Douglas Bryman, M. Ardebili, T. F. Kycia, Motoki Kobayashi, James Frank, J. M. Poutissou, S. Kabe, C. Witzig, Y. Yoshimura, M. V. Diwan, J. S. Haggerty, A. J.S. Smith, T. Inagaki, L. S. Littenberg, Ewart W. Blackmore, R. Soluk, P. D. Meyers, Norihito Muramatsu, Y. Kuno, T. Nakano, P. Padley, A. Sambamurti, R. Poutissou, Daniel Robert Marlow, A. Konaka, M. M. Ito, and T. Shinkawa

Subjects
Physics, Muon, Branching fraction, Radiative decay, Structure (category theory), General Physics and Astronomy, Absolute value (algebra), Atomic physics, Photon energy, Kinetic energy
Abstract

We report the first measurement of a structure-dependent component in the decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\gamma}$. Using the kinematic region where the muon kinetic energy is greater than 137 MeV and the photon energy is greater than 90 MeV, we find that the absolute value of the sum of the vector and axial-vector form factors is $|{F}_{V}{+F}_{A}|\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.165\ifmmode\pm\else\textpm\fi{}0.007\ifmmode\pm\else\textpm\fi{}0.011$. This corresponds to a branching ratio of $B({\mathrm{SD}}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(1.33\ifmmode\pm\else\textpm\fi{}0.12\ifmmode\pm\else\textpm\fi{}0.18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. We also set the limit $\ensuremath{-}0.04l{F}_{V}{\ensuremath{-}F}_{A}l0.24$ at $90%$ C.L.

Published
2000

10. Observation of the DecayK+→π+μ+μ−

Author

J. S. Frank, A. Stevens, M. R. Convery, Peter Daniel Meyers, M. Ardebili, Mats A Selen, L. S. Littenberg, Ewart W. Blackmore, A. S. Turcot, D. S. Akerib, P. Kitching, R. A. McPherson, M. M. Ito, P. Padley, J. S. Haggerty, S. S. Adler, A. J.S. Smith, J. M. Poutissou, R. C. Strand, L. Felawka, R. Soluk, I. H. Chiang, T. Numao, R. Poutissou, W. C. Louis, T. F. Kycia, J. A. Macdonald, T. Nakano, Y. Kuno, A. Sambamurti, M. S. Atiya, J. Roy, K. K. Li, Daniel Robert Marlow, Douglas Bryman, C. Witzig, M. Rozon, F. C. Shoemaker, and A. Konaka

Subjects
Semileptonic decay, Physics, Quantum chromodynamics, Chiral symmetry, Particle physics, Chiral perturbation theory, Unitarity, Branching fraction, General Physics and Astronomy, Particle decay, Crystallography, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Atomic physics, Perturbation theory
Abstract

The first observation of the decay K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} is reported. A total of 31 events was observed with an estimated background of 5.1{plus_minus}3.3 events in the {pi}{sup +} momentum range from 100 to 180 MeV/{ital c}. The corresponding partial branching ratio, B(K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} ,100 MeV/c{lt}P{sub {pi}{sup +} }{lt}180 MeV/c) , is [6.0{plus_minus}1.5(stat){plus_minus}0.7 (syst)]{times}10{sup {minus}7} . No K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} decay was observed in the {pi}{sup +} momentum region greater than 215 MeV/{ital c}. The observed {pi}{sup +} momentum spectrum is compared with the predictions of chiral perturbation theory. {copyright} {ital 1997} {ital The American Physical Society}

Published
1997

11. Evidence for the DecayK+→π+νν¯

Author

Ewart W. Blackmore, R. A. McPherson, S. H. Kettell, Y. Kuno, P. D. Meyers, J. S. Haggerty, Masaaki Kobayashi, Norihito Muramatsu, M. Kuriki, A. Stevens, A. J.S. Smith, P. C. Bergbusch, J. Roy, R. Poutissou, Stephen L. Adler, R. Soluk, T. Shinkawa, J. M. Poutissou, T. Nakano, T. Sato, J. R. Stone, George Redlinger, L. S. Littenberg, T. Numao, A. Sambamurti, A. O. Bazarko, M. R. Convery, Y. Kishi, J. A. Macdonald, M. Aoki, T. Inagaki, M. V. Diwan, S. Sugimoto, Daniel Robert Marlow, M. Ardebili, M. S. Atiya, Y. Yoshimura, A. Konaka, A. S. Turcot, J. Mildenberger, R. C. Strand, I-H. Chiang, T. K. Komatsubara, F. C. Shoemaker, C. Ng, M. M. Ito, T. F. Kycia, James Frank, P. Padley, P. Kitching, S. Kabe, K. K. Li, Douglas Bryman, and C. Witzig

Subjects
Momentum, Physics, Particle physics, Pion, Branching fraction, General Physics and Astronomy
Abstract

An event consistent with the signature expected for the rare kaon decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ has been observed. In the pion momentum region examined, $211lPl230\mathrm{MeV}/c$, the backgrounds are estimated to contribute $0.08\ifmmode\pm\else\textpm\fi{}0.03$ events. If the event is due to ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, the branching ratio is ${4.2}_{\ensuremath{-}3.5}^{+9.7}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$.

Published
1997

12. Search for the DecayK+→π+νν¯

Author

I. H. Chiang, L. S. Littenberg, S. S. Adler, M. S. Atiya, D. S. Akerib, A. S. Turcot, R. Soluk, K. K. Li, Douglas Bryman, A. Sambamurti, Mats A Selen, A. Stevens, L. Felawka, T. Numao, C. Witzig, Y. Kuno, V. A. Kujala, Robert McPherson, M. M. Ito, M. R. Convery, J. S. Haggerty, T. Nakano, Ewart W. Blackmore, P. Kitching, Daniel Robert Marlow, F. C. Shoemaker, R. C. Strand, A. Konaka, M. Ardebili, R. Poutissou, J. M. Poutissou, T. F. Kycia, A. J.S. Smith, James Frank, W. C. Louis, J. A. Macdonald, P. Padley, J. Roy, and P. D. Meyers

Subjects
Physics, Particle physics, Pion, Overline, Branching fraction, Nuclear Theory, High Energy Physics::Phenomenology, Pi, General Physics and Astronomy, High Energy Physics::Experiment, Limit (mathematics), Nuclear Experiment
Abstract

An upper limit on the branching ratio for the decay $K^+ \! \rightarrow \! \pi^+ \nu \overline{\nu}$ is set at $2.4 \times 10^{-9}$ at the 90\% C.L. using pions in the kinematic region $214~{\rm MeV}/c 0$.

Published
1996

13. Measurement of theπ+→e+νbranching ratio

Author

R. A. Burnham, Shama Ahmad, A. Olin, J. A. Macdonald, Douglas Bryman, P. Kitching, T. Numao, E. T. H. Clifford, Dave Britton, Y. Kuno, J. M. Poutissou, and M. S. Dixit

Subjects
Physics, Particle physics, Thesaurus (information retrieval), Branching fraction, Neutrino
Published
1994

14. Search for massive neutrinos in the decayπ→eν

Author

L. S. Littenberg, A. Sher, C. Malbrunot, T. Sullivan, S. H. Kettell, D. Vavilov, C. Hurst, N. Ito, Luca Doria, R. Poutissou, Song Chen, Masaharu Aoki, Minoru Yoshida, T. Numao, P. Gumplinger, Ahmed Hussein, Leonid Kurchaninov, Y. Igarashi, Douglas Bryman, Koji Yamada, M. Ding, and M. Blecher

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Branching fraction, 01 natural sciences, 7. Clean energy, Massless particle, Nuclear physics, Particle decay, Pion, Antimatter, 0103 physical sciences, High Energy Physics::Experiment, Neutrino, 010306 general physics, Lepton
Abstract

The positron spectrum from the decay ..pi../sup +/..-->..e/sup +/..nu../sub e/ has been examined for evidence of peaks arising from an admixture in the ..nu../sub e/ weak eigenstate of massive neutrinos. Limits on the intensity of such peaks, together with the measured ..pi -->..e..nu.. branching ratio, have been used to derive constraints on the neutrino mixing parameters over the range 4 MeV

Published
2011

15. Search for the decaysK+→π+νν¯andK+→π+X0for150<MX0<250MeV/c2

Author

A. S. Turcot, P. Padley, T. Numao, Daniel Robert Marlow, A. Konaka, R. C. Strand, A. Stevens, Peter Daniel Meyers, J. A. Macdonald, L. S. Littenberg, Mats A Selen, M. M. Ito, J. Roy, R. Poutissou, D. S. Akerib, I-Hung Chiang, J. M. Poutissou, W. C. Louis, Y. Kuno, M. S. Atiya, Ewart W. Blackmore, R. Soluk, J. S. Haggerty, F. C. Shoemaker, L. Felawka, A. Sambamurti, K. K. Li, A. J.S. Smith, Douglas Bryman, P. Kitching, T. F. Kycia, and James Frank

Subjects
Physics, Antiparticle, Particle physics, Particle decay, Crystallography, Pion, Meson, Branching fraction, Hadron, Elementary particle, Boson
Abstract

A search for the decays ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ and ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{X}^{0}$, where ${X}^{0}$ is any weakly interacting neutral particle or system of neutral particles with $150l{M}_{{X}^{0}}l250$ MeV/${\mathit{c}}^{2}$, was performed in the pion kinematic region below the ${K}_{\ensuremath{\pi}2}({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0})$ peak. An upper limit on $B({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}})$ is set at 1.7 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ (90% C.L.) and $B({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{X}^{0})$ is restricted to the ${10}^{\ensuremath{-}7}$ level or lower. Limits are also set for the production of ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ through scalar or tensor interactions at 1.8 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ and 1.0 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ (90% C.L.), respectively.

Published
1993

16. Search for the DecayK+→π+νν¯

Author

Ewart W. Blackmore, Y. Kuno, W. C. Louis, T. F. Kycia, K. K. Li, Douglas Bryman, L. Felawka, M. M. Ito, J. S. Haggerty, I-Hung Chiang, A. S. Turcot, James Frank, A. J.S. Smith, Daniel Robert Marlow, F. C. Shoemaker, P. Padley, A. Konaka, Mats A Selen, A. Sambamurti, M. S. Atiya, P. Kitching, J. Roy, R. Soluk, R. C. Strand, P. D. Meyers, T. Numao, A. Stevens, J. M. Poutissou, L. S. Littenberg, D. S. Akerib, R. Poutissou, and J. A. Macdonald

Subjects
Physics, Semileptonic decay, Particle physics, Meson, Branching fraction, Particle model, General Physics and Astronomy, Massless particle, Combinatorics, Particle decay, Pion, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Pi, Neutral particle, Bar (unit)
Abstract

An upper limit on the branching ratio for the decay [ital K][sup +][r arrow][pi][sup +][nu][bar [nu]] is set at 7.5[times]10[sup [minus]9] (90% C.L.) using the kinematic region above the [ital K][sub [pi]2]([ital K][sup +][r arrow][pi][sup +][pi][sup 0]) peak. When combined with our result from below the [ital K][sub [pi]2] peak, we obtain the limit 5.2[times]10[sup [minus]9]. An upper limit of 1.7[times]10[sup [minus]9] is also found on the branching ratio for decays of the form [ital K][sup +][r arrow][pi][sup +][ital X0] where [ital X][sup 0] is any massless, weakly interacting neutral particle. Limits are also set for cases where [ital M][sub [ital X]][sup 0][gt]0.

Published
1993

17. Measurement of theK+→π0μ+νμγbranching ratio

Author

Y. Yoshimura, T. Nomura, Vivek Jain, M. M. Ito, P. Kitching, C. Witzig, K. Shimada, James Frank, M. Kuriki, J. R. Stone, A. Konaka, T. Shinkawa, P. C. Bergbusch, Yoichi Tamagawa, S. Sugimoto, J. Mildenberger, R. C. Strand, T. K. Komatsubara, A. O. Bazarko, I. H. Chiang, T. Shimoyama, Song Chen, Y. Kuno, S. H. Kettell, T. Fujiwara, M. Miyajima, T. Tsunemi, Masaaki Kobayashi, C. Ng, K. K. Li, Douglas Bryman, M. V. Diwan, J. Hu, R. Poutissou, S. Kabe, S. Ng, T. Inagaki, Ewart W. Blackmore, J. M. Poutissou, T. Numao, J. A. Macdonald, F. C. Shoemaker, T. Sato, L. S. Littenberg, P. D. Meyers, Norihito Muramatsu, G. Redlinger, S. S. Adler, J. S. Haggerty, T. Nakano, and D. E. Jaffe

Subjects
Physics, Nuclear and High Energy Physics, Antiparticle, Muon, Branching fraction, Astrophysics::High Energy Astrophysical Phenomena, Particle decay, Pion, Antimatter, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Energy (signal processing), Dimensionless quantity
Abstract

A measurement of the decay K{sup +{yields}{pi}0{mu}+{nu}}{sub {mu}{gamma}}has been performed with the E787 detector at Brookhaven National Laboratory. Forty events were observed in the signal region with the background expectation of (16.5{+-}2.7) events. The branching ratio was measured to be (1.58{+-}0.46(stat.){+-}0.08(syst.))x10{sup -5} in the kinematic region E{sub {gamma}>}30 MeV and {theta}{sub {mu}{gamma}>}20 deg., where E{sub {gamma}}is the energy of the emitted photon and {theta}{sub {mu}{gamma}}is the angle between the muon and the photon in the K{sup +} rest frame. The results were consistent with theoretical predictions.

Published
2010

18. Search for the decayπ0→γ+X

Author

P. Kitching, J. S. Haggerty, K. K. Li, Daniel Robert Marlow, L. Felawka, Douglas Bryman, Mats A Selen, R. Poutissou, A. J.S. Smith, T. F. Kycia, J. M. Poutissou, Y. Kuno, A. Konaka, Ewart W. Blackmore, T. Numao, R. C. Strand, W. C. Louis, J. A. Macdonald, J. Roy, M. M. Ito, A. Sambamurti, J. S. Frank, F. C. Shoemaker, M. S. Atiya, A. J. Stevens, I. H. Chiang, A. S. Turcot, P. Padley, L. S. Littenberg, D. S. Akerib, and P. D. Meyers

Subjects
Physics, Nuclear physics, Pion, Branching fraction, General Physics and Astronomy, Elementary particle, Neutral vector, Two-body problem, Three-body problem, Neutral particle, Upper and lower bounds
Abstract

A search for the decay π 0 →γX, where X is any long-lived weakly interacting neutral vector particle with mass smaller than the neutral pion mass, was performed using neutral pions tagged by K + →π + π 0 . A 90%-C.L. upper limit for the branching ratio of the two-body decay B(π 0 →γX)

Published
1992

19. Measurement of theπ+→e+ν branching ratio

Author

R. A. Burnham, Y. Kuno, J. M. Poutissou, Shama Ahmad, P. Kitching, D. I. Britton, E. T. H. Clifford, Douglas Bryman, T. Numao, A. Olin, J. A. Macdonald, and M. S. Dixit

Subjects
Combinatorics, Physics, Particle decay, Antiparticle, Particle physics, Muon, Meson, Branching fraction, Hadron, Energy spectrum, General Physics and Astronomy, Time spectrum
Abstract

A new measurement of the ${\mathrm{\ensuremath{\pi}}}^{+}$\ensuremath{\rightarrow}${\mathit{e}}^{+}$\ensuremath{\nu} branching ratio gives ${\mathit{R}}_{\mathrm{\ensuremath{\pi}}\mathit{e}\ensuremath{\nu}}$=\ensuremath{\Gamma}(\ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu}+\ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu}\ensuremath{\gamma})/\ensuremath{\Gamma} (\ensuremath{\pi}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\nu}+\ensuremath{\pi}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\nu}\ensuremath{\gamma}) =[1.2265\ifmmode\pm\else\textpm\fi{}0.0034(stat)\ifmmode\pm\else\textpm\fi{}0.0044(sys)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$. This result is in agreement with standard model calculations and confirms the hypothesis of electron-muon universality at the 0.2% level.

Published
1992

20. Further Search for the DecayK+→π+νν¯

Author

S. Adler, M. S. Atiya, I-H. Chiang, M. V. Diwan, J. S. Frank, J. S. Haggerty, V. Jain, S. H. Kettell, T. F. Kycia, K. K. Li, L. S. Littenberg, C. Ng, R. C. Strand, C. Witzig, M. Kazumori, T. K. Komatsubara, M. Kuriki, N. Muramatsu, A. Otomo, S. Sugimoto, T. Inagaki, S. Kabe, M. Kobayashi, Y. Kuno, T. Sato, T. Shinkawa, Y. Yoshimura, Y. Kishi, T. Nakano, T. Sasaki, M. Ardebili, A. O. Bazarko, M. R. Convery, M. M. Ito, D. R. Marlow, R. A. McPherson, P. D. Meyers, F. C. Shoemaker, A. J. S. Smith, J. R. Stone, M. Aoki, P. C. Bergbusch, E. W. Blackmore, D. A. Bryman, A. Konaka, J. A. Macdonald, J. Mildenberger, T. Numao, P. Padley, J.-M. Poutissou, R. Poutissou, G. Redlinger, P. Kitching, and R. Soluk

Subjects
Physics, Antiparticle, Particle decay, Particle physics, Pion, Meson, Branching fraction, Hadron, General Physics and Astronomy, Neutrino, Lepton
Abstract

A search for additional evidence for the rare kaon decay K+-->pi(+)nunu; has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event. No new events were found in the pion momentum region examined, 211 pi(+)nunu;) = 1.5(+3.4)(-1.2)x10(-10).

Published
2000

21. Study of the decayK+→π+νν¯in the momentum region140<Pπ<199 MeV/c

Author

I. H. Chiang, Y. Yoshimura, O. V. Mineev, S. H. Kettell, S. Sugimoto, Tamaki Yoshioka, Norihito Muramatsu, J. Ives, E. J. Ramberg, V. A. Mukhin, T. Numao, A. Kushnirenko, V. Obraztsov, L. S. Littenberg, J. Hu, M. V. Diwan, M. M. Khabibullin, B. Lewis, T. Nakano, S. V. Petrenko, J. A. Macdonald, B. Bassalleck, Yu. G. Kudenko, T. Sato, T. Tsunemi, D. E. Jaffe, J. Mildenberger, R. Tschirhart, R. C. Strand, M. Miyajima, A. N. Khotjantsev, K. Mizouchi, A. P. Kozhevnikov, T. K. Komatsubara, Yoichi Tamagawa, Song Chen, Ewart W. Blackmore, T. Shinkawa, N. V. Yershov, D. V. Vavilov, T. Sekiguchi, Takashi Nomura, D. I. Patalakha, T. Fujiwara, A. Konaka, Masaaki Kobayashi, A. V. Artamonov, I. A. Christidi, Zhe Wang, R. Poutissou, Masaharu Nomachi, B. Viren, P. Kitching, B. Bhuyan, S. Kabe, K. K. Li, L. G. Landsberg, Douglas Bryman, P. S. Cooper, James Frank, George Redlinger, and K. Omata

Subjects
Physics, Nuclear and High Energy Physics, Particle decay, Particle physics, Pion, Meson, Branching fraction, Hadron, Elementary particle, Dimensionless quantity, Lepton
Abstract

Experiment E949 at Brookhaven National Laboratory has observed three new events consistent with the decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ in the pion momentum region $140l{P}_{\ensuremath{\pi}}l199\text{ }\text{ }\mathrm{MeV}/c$ in an exposure of $1.71\ifmmode\times\else\texttimes\fi{}{10}^{12}$ stopped kaons with an estimated total background of $0.93\ifmmode\pm\else\textpm\fi{}0.17(\mathrm{stat}{)}_{\ensuremath{-}0.24}^{+0.32}(\mathrm{syst})$ events. This brings the total number of observed ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ events to seven. Combining this observation with previous results, assuming the pion spectrum predicted by the standard model, results in a branching ratio of $\mathcal{B}({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}})=({1.73}_{\ensuremath{-}1.05}^{+1.15})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$. An interpretation of the results for alternative models of the decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}+nothing$ is also presented.

Published
2009

22. Upper limit on the branching ratio for the decayπ0→νν¯

Author

Daniel Robert Marlow, Georges Azuelos, Ewart W. Blackmore, R. C. Strand, T. Numao, W. C. Louis, L. S. Littenberg, Mats A Selen, J. Roy, I. H. Chiang, A. J. Stevens, T. F. Kycia, D. S. Akerib, Y. Kuno, R. Poutissou, Peter Daniel Meyers, L. Felawka, K. K. Li, Douglas Bryman, J. S. Frank, J. A. Macdonald, J. S. Haggerty, P. Padley, A. J.S. Smith, M. S. Atiya, P. Kitching, F. C. Shoemaker, J. M. Poutissou, and M. M. Ito

Subjects
Physics, Particle decay, Antiparticle, Pion, Meson, Branching fraction, General Physics and Astronomy, High Energy Physics::Experiment, Atomic physics, Weak interaction, Energy (signal processing), Lepton
Abstract

An experimental upper limit on the branching ratio for the decay {pi}{sup 0}{r arrow}{nu}{bar {nu}} is set at 8.3{times}10{sup {minus}7} (90% C.L.). This decay is forbidden if neutrinos are purely left handed. The limit also applies to any decays of the {pi}{sup 0} to weakly interacting neutrals.

Published
1991

23. New Measurement of theK+→π+νν¯Branching Ratio

Author

A. Kushnirenko, J. Ives, T. Numao, E. J. Ramberg, Tamaki Yoshioka, Ewart W. Blackmore, J. A. Macdonald, T. Tsunemi, B. Bassalleck, K. K. Li, Song Chen, Y. Yoshimura, J. Mildenberger, R. Poutissou, Douglas Bryman, R. C. Strand, A. P. Kozhevnikov, T. K. Komatsubara, Yoichi Tamagawa, D. E. Jaffe, A. V. Artamonov, I. A. Christidi, T. Shinkawa, D. I. Patalakha, N. V. Yershov, O. V. Mineev, T. Sekiguchi, A. N. Khotjantsev, George Redlinger, K. Mizouchi, T. Nomura, A. Konaka, R. Tschirhart, Zhe Wang, I. H. Chiang, K. Omata, S. H. Kettell, T. Fujiwara, Norihito Muramatsu, V. Obraztsov, M. M. Khabibullin, M. V. Diwan, Masaaki Kobayashi, V. A. Mukhin, L. S. Littenberg, Yu. G. Kudenko, S. Sugimoto, T. Sato, J. Hu, James Frank, Masaharu Nomachi, B. Lewis, T. Nakano, M. Miyajima, S. V. Petrenko, P. Kitching, P. S. Cooper, B. Viren, B. Bhuyan, S. Kabe, D. V. Vavilov, and L. G. Landsberg

Subjects
Physics, Nuclear physics, Particle decay, Pair production, Pion, Meson, Branching fraction, Hadron, General Physics and Astronomy, Dimensionless quantity, Lepton
Abstract

Three events for the decay K+-->pi+ nunu have been observed in the pion momentum region below the K+-->pi+pi0 peak, 140 pi+ nunu) = (1.73(-1.05)+1.15) x 10(-10) consistent with the standard model prediction.

Published
2008

24. Measurement of theK+→π+νν¯branching ratio

Author

V. Obraztsov, M. M. Khabibullin, M. Ardebili, A. V. Artamonov, T. Numao, A. Konaka, S. S. Adler, P. S. Cooper, A. Kushnirenko, I. H. Chiang, Song Chen, S. H. Kettell, James Frank, A. O. Bazarko, M. Kuriki, K. Omata, J. A. Macdonald, B. Bassalleck, M. S. Atiya, T. Sekiguchi, J. Mildenberger, R. C. Strand, A. P. Kozhevnikov, T. K. Komatsubara, T. Sato, Ewart W. Blackmore, O. V. Mineev, M. Aoki, M. R. Convery, Masaharu Nomachi, P. D. Meyers, D. E. Jaffe, Y. Yoshimura, Yoichi Tamagawa, B. Viren, T. Shinkawa, Norihito Muramatsu, K. Mizouchi, M. Kazumori, George Redlinger, P. Kitching, B. Bhuyan, L. S. Littenberg, F. C. Shoemaker, M. Miyajima, Tamaki Yoshioka, J. R. Stone, V. A. Mukhin, J. Hu, Masaaki Kobayashi, N. V. Yershov, B. Lewis, T. Nakano, S. V. Petrenko, K. K. Li, A. N. Khotjantsev, Douglas Bryman, Y. Kuno, A. P. Ivashkin, Takashi Nomura, Daniel Robert Marlow, T. Fujiwara, S. Kabe, R. Poutissou, E. J. Ramberg, M. M. Ito, T. Tsunemi, D. I. Patalakha, S. Sugimoto, V. V. Anisimovsky, D. V. Vavilov, R. A. McPherson, I. A. Christidi, L. G. Landsberg, R. Tschirhart, J. S. Haggerty, A. J.S. Smith, T. Inagaki, M. V. Diwan, and Yu. G. Kudenko

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Particle decay, Crystallography, Pion, Meson, Branching fraction, Hadron, Elementary particle, Lepton, Dimensionless quantity
Abstract

Experiment E949 at Brookhaven National Laboratory studied the rare decay K{sup +}-->pi{sup +} nu{ovr {nu}} and other processes with an exposure of 1.77 x 10{sup 12} k{sup +}'s. The data were analyzed using a blind analysis technique yielding one candidate event with an estimated background of 0.30 {+-} 0.03 events. Combining this result with the observation of two candidate events by the predecessor experiment E787 gave the branching ratio B(K{sup +}-->pi{sup +} nu{ovr {nu}}) = (1.47{sub -0.89}{sup +1.30}) x 10{sup -10}, consistent with the standard model prediction of (0.74 {+-} 0.20) x 10{sup -10}. This is a more detailed report of results previously published [V.V. Anisimovsky et al., Phys. Rev. Lett. 93, 031801 (2004)].

Published
2008

25. Search for the decayK+→π+γγ

Author

T. F. Kycia, I. H. Chiang, Ewart W. Blackmore, Daniel Robert Marlow, T. Numao, Georges Azuelos, Peter Daniel Meyers, W. C. Louis, M. S. Atiya, Y. Kuno, R. C. Strand, K. K. Li, A. J. Stevens, Douglas Bryman, M. M. Ito, R. Poutissou, P. Padley, J. S. Haggerty, Mats A Selen, A. J.S. Smith, J. M. Poutissou, J. S. Frank, J. A. Macdonald, J. Roy, F. C. Shoemaker, P. Kitching, L. S. Littenberg, L. Felawka, and D. S. Akerib

Subjects
Nuclear physics, Physics, Energy distribution, Phase space, Energy spectrum, Pi, General Physics and Astronomy, Scalar boson, Neutral particle, Kinetic energy, Gamma gamma
Published
1990

26. Search for the decayK+→π+νν¯

Author

J. S. Haggerty, A. J.S. Smith, R. Poutissou, Ewart W. Blackmore, P. Padley, W. C. Louis, Selen, F. C. Shoemaker, T. Numao, Georges Azuelos, A. Stevens, J. A. Macdonald, Daniel Robert Marlow, Atiya, J. M. Poutissou, M. M. Ito, L. Felawka, P. Kitching, T. F. Kycia, James Frank, R. C. Strand, P. D. Meyers, L. S. Littenberg, D. S. Akerib, I-Hung Chiang, Y. Kuno, J. Roy, K. K. Li, and Douglas Bryman

Subjects
Semileptonic decay, Physics, Particle physics, Crystallography, Particle decay, Pion, Meson, Branching fraction, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Hadron, General Physics and Astronomy, Elementary particle, Particle identification
Abstract

An upper limit on the branching ratio for the decay {ital K}{sup +}{r arrow}{pi}{sup +}{nu}{bar {nu}} is set at 3.4{times}10{sup {minus}8} (90% C.L.). In addition, a 90%-C.L. upper limit of 6.4{times}10{sup {minus}9} is set on the branching ratio for decays of the form {ital K}{sup +}{r arrow}{pi}{sup +}{ital X}{sup 0}, where {ital X}{sup 0} is any massless, weakly interacting neutral particle. Limits are also set for the case where {ital M}{sub {ital X}{sup 0}}{gt}0.

Published
1990

27. π−nuclear capture ratio on hydrogen and oxygen in water

Author

Yu. I. Davydov, S. Ovchinnikov, J. M. Poutissou, S. Berridge, R. A. Gearhart, Yuri Efremenko, Terry C Awes, V. Cianciolo, W. Bugg, and T. Numao

Subjects
Physics, Mass number, Hydrogen, chemistry, Analytical chemistry, chemistry.chemical_element, Atomic physics, Oxygen, Atomic and Molecular Physics, and Optics
Abstract

We report on a measurement of the {pi}{sup -} nuclear capture ratio on hydrogen and oxygen in water by two methods. The capture ratio is measured to be W{sub H{sub 2}}{sub O}=(4.45{+-}0.24)x10{sup -3}.

Published
2007

28. Upper limit on the branching ratio for the decayπ0→νν¯

Author

Yoichi Tamagawa, A. Kushnirenko, I. H. Chiang, S. H. Kettell, George Redlinger, R. Poutissou, A. V. Artamonov, T. Shinkawa, V. A. Mukhin, D. V. Vavilov, D. I. Patalakha, Masaaki Kobayashi, M. V. Diwan, Masaharu Nomachi, L. G. Landsberg, E. J. Ramberg, B. Lewis, T. Nakano, B. Viren, Ewart W. Blackmore, S. V. Petrenko, P. S. Cooper, Yu. G. Kudenko, D. E. Jaffe, A. N. Khotjantsev, Tamaki Yoshioka, S. Sugimoto, J. Hu, A. Konaka, O. V. Mineev, T. Sato, T. Fujiwara, V. Obraztsov, T. Nomura, M. Miyajima, T. Sekiguchi, K. Mizouchi, Y. Yoshimura, T. Numao, I. A. Christidi, R. Tschirhart, J. A. Macdonald, B. Bassalleck, N. V. Yershov, S. Kabe, James Frank, P. Kitching, B. Bhuyan, J. Mildenberger, R. C. Strand, A. P. Kozhevnikov, T. K. Komatsubara, K. Omata, K. K. Li, Douglas Bryman, T. Tsunemi, M. M. Khabibullin, Norihito Muramatsu, L. S. Littenberg, and Song Chen

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Classical mechanics, Branching fraction, Limit (mathematics), Helicity, Particle identification
Abstract

A sample of kinematically identified K{sup +}{yields}{pi}{sup +}{pi}{sup 0} decays obtained with the E949 detector was used to search for the helicity-suppressed decay {pi}{sup 0}{yields}{nu}{nu} resulting in an upper limit of 2.7x10{sup -7} at 90% confidence level. The upper limit is also applicable to {pi}{sup 0} decays into unknown weakly-interacting particles.

Published
2005

29. Further search for the decayK+→π+νν¯in the momentum regionP<195MeV/c

Author

Vivek Jain, L. S. Littenberg, P. Kitching, B. Bhuyan, P. C. Bergbusch, J. S. Frank, Yoshitaka Kuno, George Redlinger, S. Kabe, Ewart W. Blackmore, K. K. Li, C. Witzig, T. Numao, A. Konaka, T. F. Kycia, Douglas Bryman, R. A. McPherson, A. Otomo, M. Kuriki, J. A. Macdonald, J. S. Haggerty, M. Aoki, R. Soluk, M. V. Diwan, S. S. Adler, T. Sato, P. D. Meyers, J. R. Stone, S. Sugimoto, S. Ng, A. J.S. Smith, I. H. Chiang, J. Mildenberger, R. C. Strand, T. K. Komatsubara, S. H. Kettell, T. Sasaki, M. Kazumori, F. C. Shoemaker, T. Inagaki, C. Ng, M. Ardebili, J. M. Poutissou, Y. Yoshimura, A. O. Bazarko, N. Muramatsu, R. Poutissou, M. S. Atiya, Masaaki Kobayashi, D. E. Jaffe, M. M. Ito, M. R. Convery, Takashi Nakano, and T. Shinkawa

Subjects
Massless particle, Momentum, Physics, Nuclear and High Energy Physics, Branching fraction, Atomic physics
Abstract

We report the results of a search for the decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ in the kinematic region with ${\ensuremath{\pi}}^{+}$ momentum $140lPl195\mathrm{MeV}/c$ using the data collected by the E787 experiment at BNL. No events were observed. When combined with our previous search in this region, one candidate event with an expected background of $1.22\ifmmode\pm\else\textpm\fi{}0.24$ events results in a 90% C.L. upper limit of $2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ on the branching ratio of ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}.$ We also report improved limits on the rates of ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{X}^{0}$ and ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{X}^{1}{X}^{2}$ where ${X}^{0}{,X}^{1}{,X}^{2}$ are hypothetical, massless, long-lived neutral particles.

Published
2004

30. Improved Measurement of theK+→π+νν¯Branching Ratio

Author

K. K. Li, T. Numao, K. Mizouchi, P. S. Cooper, J. A. Macdonald, Takashi Nakano, Douglas Bryman, E. J. Ramberg, Masaharu Nomachi, B. Bassalleck, S. Sugimoto, V. V. Anisimovsky, Yoichi Tamagawa, R. Poutissou, Tamaki Yoshioka, O. V. Mineev, N. V. Yershov, T. Nomura, T. Tsunemi, D. V. Vavilov, R. Tschirhart, L. G. Landsberg, Y. Yoshimura, J. S. Frank, I. A. Christidi, N. Muramatsu, A. Kushnirenko, Ewart W. Blackmore, D. I. Patalakha, George Redlinger, A. N. Khotjantsev, A. Konaka, T. Shinkawa, V. Obraztsov, T. Fujiwara, A. V. Artamonov, M. V. Diwan, B. Bhuyan, J. Hu, S. Kabe, M. Miyajima, M. M. Khabibullin, Yu. G. Kudenko, T. Sato, T. Sekiguchi, K. Omata, L. S. Littenberg, I. H. Chiang, S. H. Kettell, Masaaki Kobayashi, Shaomin Chen, A. P. Ivashkin, B. Viren, V. A. Mukhin, B. Lewis, S. V. Petrenko, D. E. Jaffe, J. Mildenberger, R. C. Strand, A. P. Kozhevnikov, T. K. Komatsubara, and P. Kitching

Subjects
Physics, Momentum, Nuclear physics, Particle physics, Pion, Branching fraction, Pi, General Physics and Astronomy, Value (computer science), National laboratory
Abstract

An additional event near the upper kinematic limit for K+ to pi+ nu nubar has been observed by Experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is B(K+ to pi+ nu nubar)= 1.47 (+1.30, - 0.89) x 10-10 based on three events observed in the pion momentum region 211

Published
2004

31. Search for the rare decayK+→π+γ

Author

R. C. Strand, M. Ardebili, T. K. Komatsubara, M. Aoki, C. Ng, Yoshitaka Kuno, A. Konaka, P. C. Bergbusch, T. Numao, Vivek Jain, M. Kazumori, M. Kuriki, Peter Daniel Meyers, R. Poutissou, S. Sugimoto, M. Miyajima, T. Sato, P. Kitching, T. F. Kycia, F. C. Shoemaker, Y. Yoshimura, T. Shinkawa, T. Sasaki, J. R. Stone, J. M. Poutissou, E. W. Blackmore, J. S. Frank, L. S. Littenberg, George Redlinger, M. V. Diwan, M. S. Atiya, N. Muramatsu, A. Otomo, J. Mildenberger, I. H. Chiang, S. H. Kettell, R. A. McPherson, R. Soluk, J. S. Haggerty, S. S. Adler, K. K. Li, M. R. Convery, Douglas Bryman, J. A. Macdonald, Masaaki Kobayashi, A. O. Bazarko, T. Nakano, C. Witzig, T. Inagaki, J. Nishide, Y. Tamagawa, M. M. Ito, and S. Kabe

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Branching fraction, High Energy Physics::Experiment
Abstract

We have performed a search for the angular-momentum forbidden decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\gamma}$ with the E787 detector at BNL. No events were observed in the ${\ensuremath{\pi}}^{+}$ kinematic region around $227 \mathrm{MeV}/c.$ An upper limit on the branching ratio for the decay is determined to be $3.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ at $90%$ confidence level.

Published
2002

32. Further Evidence for the DecayK+→π+νν¯

Author

Vivek Jain, J. R. Stone, P. Kitching, Yoichi Tamagawa, G. Redlinger, J. Hu, M. Kuriki, J. Mildenberger, R. C. Strand, I. H. Chiang, Shaomin Chen, Y. Yoshimura, T. K. Komatsubara, S. H. Kettell, K. Shimada, S. Ng, S. S. Adler, J. S. Frank, J. S. Haggerty, Ewart W. Blackmore, P. C. Bergbusch, C. Witzig, T. Shinkawa, T. Shimoyama, M. Miyajima, K. K. Li, Takashi Nakano, Douglas Bryman, A. Konaka, T. Inagaki, T. Sato, M. V. Diwan, Motoki Kobayashi, A. O. Bazarko, S. Sugimoto, Y. Kuno, S. Kabe, T. Numao, J. A. Macdonald, F. C. Shoemaker, J. M. Poutissou, L. S. Littenberg, P. D. Meyers, Norihito Muramatsu, R. Poutissou, C. Ng, and M. M. Ito

Subjects
Physics, Particle physics, Pion, Branching fraction, Pi, General Physics and Astronomy, Sensitivity (control systems)
Abstract

Additional evidence for the rare kaon decay ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ has been found in a new data set with comparable sensitivity to the previously reported result. One new event was observed in the pion momentum region examined, $211lPl229\mathrm{MeV}/c$, bringing the total for the combined data set to two. Including all data taken, the backgrounds were estimated to contribute $0.15\ifmmode\pm\else\textpm\fi{}0.05$ events. The branching ratio is $B({K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\ensuremath{\nu}\overline{\ensuremath{\nu}}){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.57}_{\ensuremath{-}0.82}^{+1.75}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$.

Published
2002

33. Search for the decayK+→π+π0νν¯

Author

T. F. Kycia, J. A. Macdonald, P. D. Meyers, George Redlinger, I. H. Chiang, C. Witzig, F. C. Shoemaker, S. H. Kettell, M. V. Diwan, T. K. Komatsubara, J. R. Stone, T. Inagaki, C. Ng, J. M. Poutissou, P. C. Bergbusch, A. Konaka, T. Numao, Y. Kuno, M. Ardebili, J. S. Haggerty, T. Nakano, M. Kuriki, P. Kitching, L. S. Littenberg, T. Shinkawa, M. M. Ito, S. Kabe, S. S. Adler, Y. Yoshimura, S. Sugimoto, T. Sato, J. S. Frank, N. Muramatsu, M. Aoki, R. Poutissou, J. Mildenberger, R. Soluk, R. C. Strand, M. Kobayashi, E. W. Blackmore, M. R. Convery, K. K. Li, R. A. McPherson, Douglas Bryman, Y. Kishi, and M. S. Atiya

Subjects
Physics, Nuclear and High Energy Physics, Mathematical physics
Published
2001

34. Improved search for massive neutrinos inπ+→e+νdecay

Author

Shama Ahmad, M. S. Dixit, D. I. Britton, J. M. Poutissou, T. Numao, J. A. Macdonald, R. A. Burnham, P. Kitching, E. T. H. Clifford, A. Olin, Y. Kuno, and Douglas Bryman

Subjects
Physics, Antiparticle, Particle physics, Particle decay, Pion, Meson, Branching fraction, High Energy Physics::Phenomenology, High Energy Physics::Experiment, Elementary particle, Neutrino, Lepton
Abstract

Evidence of massive neutrinos was sought in the ${\ensuremath{\pi}}^{+}\ensuremath{\rightarrow}{e}^{+}\ensuremath{\nu}$ decay spectrum with the background from the $\ensuremath{\pi}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\rightarrow}e$ decay chain highly suppressed. Upper limits (90% C.L.) were set on the neutrino mixing parameter ${|{U}_{\mathrm{ei}}|}^{2}l{10}^{\ensuremath{-}7}$ in the mass region $50l{m}_{\ensuremath{\nu}}l130$ MeV/${\mathit{c}}^{2}$.

Published
1992

35. Upper limit on the decayK+→e+νμ+μ−

Author

T. Numao, A. S. Turcot, J. A. Macdonald, S. S. Adler, Ewart W. Blackmore, P. D. Meyers, Y. Kuno, J. Roy, T. Nakano, L. Felawka, A. Sambamurti, F. C. Shoemaker, Mats A Selen, M. S. Atiya, Daniel Robert Marlow, J. S. Haggerty, J. S. Frank, M. Rozon, A. Stevens, J. M. Poutissou, A. Konaka, M. M. Ito, R. Soluk, L. S. Littenberg, I. H. Chiang, D. S. Akerib, P. Padley, C. Witzig, R. Poutissou, A. J.S. Smith, W. C. Louis, Robert McPherson, P. Kitching, M. E. Convery, K. K. Li, T. F. Kycia, Douglas Bryman, R. C. Strand, and M. Ardebili

Subjects
Physics, Nuclear and High Energy Physics, Chiral symmetry, Chiral perturbation theory, Branching fraction, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Limit (mathematics), Atomic physics, Perturbation theory, Helicity, Standard Model
Abstract

An upper limit on the branching ratio for the decay K{sup +}{r_arrow}e{sup +}{nu}{mu}{sup +}{mu}{sup {minus}} is set at 5.0{times}10{sup {minus}7} at a 90{percent} confidence level, consistent with predictions from chiral perturbation theory. {copyright} {ital 1998} {ital The American Physical Society}

Published
1998

36. Search for massive neutrinos inπ+→μ+ν decay

Author

T. Numao and Douglas Bryman

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Antiparticle, Particle decay, Crystallography, Meson, Branching fraction, Antimatter, Hadron, Elementary particle, Lepton
Abstract

Evidence of massive neutrinos was sought in the {pi}{sup +}{implies}{mu}{sup +}{ital x} decay spectrum in the mass region {ital M}{sub {ital x}}=30{endash}33.91 MeV/{ital c}{sup 2}. Upper limits on the branching ratio {ital R}{sub {mu}}{sub {ital x}}{le}(4{endash}6){times}10{sup -}{sup 5} (90{percent} C.L.) were set for this region, which correspond to the neutrino mixing parameter {vert_bar}{ital U}{sub {mu}}{sub {ital x}}{vert_bar}{sup 2}{much_gt}10{sup -}{sup 3}{endash}10{sup -}{sup 4}. {copyright} {ital 1995 The American Physical Society.}

Published
1996

37. Search for muon-electron and muon-positron conversion

Author

J. M. Poutissou, Georges Azuelos, P. Depommier, T. Numao, H. Mes, R. Poutissou, E. T. H. Clifford, J. A. Macdonald, J. Spuller, M. Blecher, R. A. Burnham, M. J. Leitch, Douglas Bryman, I. Navon, Shafqat Ahmad, M. S. Dixit, C. K. Hargrove, M. D. Hasinoff, K. Gotow, J. Summhammer, and P. Schlatter

Subjects
Nuclear reaction, Physics, Antiparticle, Positron, Muon, Branching fraction, High Energy Physics::Phenomenology, High Energy Physics::Experiment, Elementary particle, Electron, Atomic physics, Lepton
Abstract

Limits on the lepton-flavor-violating reactions ${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$+Z\ensuremath{\rightarrow}${e}^{\mathrm{\ensuremath{-}}}$+Z and ${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$+Z\ensuremath{\rightarrow}${e}^{+}$+(Z-2), muon-electron and muon-positron conversion, have been obtained from a search performed at TRIUMF using a time-projection chamber. Upper limits (90% C.L.) for the branching ratios compared to ordinary muon capture for a titanium target are R---(Ti)=\ensuremath{\Gamma}(${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$Ti\ensuremath{\rightarrow}${\mathit{e}}^{\mathrm{\ensuremath{-}}}$Ti)/\ensuremath{\Gamma}(${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$Ti capture)4.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ and ${\mathit{R}}_{+}$(Ti)=\ensuremath{\Gamma}(${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$Ti\ensuremath{\rightarrow}${\mathit{e}}^{+}$Ca*)/\ensuremath{\Gamma}(${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$Ti capture).1.7\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ A smaller data set obtained using a lead target yielded ${R}_{\mathrm{\ensuremath{-}}}$(Pb)4.9\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$. The implications of these results for extensions of the standard model which allow lepton-flavor violation are discussed.

Published
1988

38. Search for a light Higgs boson in the decayK+→π+H, H→μ+μ−

Author

T. Numao, Mats A Selen, R. Poutissou, F. C. Shoemaker, R. C. Strand, J. M. Poutissou, Peter Daniel Meyers, I. H. Chiang, J. S. Frank, Y. Kuno, J. A. Macdonald, J. Roy, T. F. Kycia, M. S. Atiya, W. C. Louis, A. J. Stevens, Georges Azuelos, J. S. Haggerty, A. J.S. Smith, Daniel Robert Marlow, K. K. Li, Douglas Bryman, M. M. Ito, P. Padley, L. S. Littenberg, D. S. Akerib, Ewart W. Blackmore, P. Kitching, L. Felawka, and Michael Hildreth

Subjects
Physics, Particle decay, Particle physics, Crystallography, Pion, Muon, Meson, Branching fraction, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Hadron, Higgs boson, General Physics and Astronomy, Elementary particle
Abstract

An upper limit on the branching ratio of the decay {ital K}{sup +}{r arrow}{pi}{sup +}H, {ital H}{r arrow}{mu}{sup +}{mu}{sup {minus}} is set at 1.5{times}10{sup {minus}7} at the 90% confidence level, for a Higgs-boson mass in the interval 220{lt}{ital m}{sub {ital H}}{lt}320 MeV/{ital c}{sup 2}. In addition, 90%-confidence-level upper limits on the branching ratios of the decays {ital K}{sup +}{r arrow}{pi}{sup +}{mu}{sup +}{mu}{sup {minus}} and {ital K}{sup +}{r arrow}{mu}{sup +}{nu}{mu}{sup +}{mu}{sup {minus}} are set at 2.3{times}10{sup {minus}7} and 4.1{times}10{sup {minus}7}, respectively.

Published
1989

39. Cross section of pair production near threshold

Author

T. Numao, Toshimitsu Yamazaki, and H. En'yo

Subjects
Physics, Cross section (physics), Pair production, chemistry, Screening effect, Atom, Detector, chemistry.chemical_element, Germanium, Nuclear cross section, Electron, Atomic physics
Abstract

The cross section of the pair production in germanium at 1064 keV, only 42 keV above threshold, has been measured with the use of a Ge(Li) detector. The obtained cross section is 0.182 mb/atom and has a large deviation from the theoretical value by \O{}verb\o{}, Mork, and Olsen. The present result suggests that the screening effect of atomic electrons has a large contribution to the pair-production cross section near threshold.

Published
1980

40. Superallowed Fermi beta transition ofGa62

Author

T. Takeda, R. Chiba, S. Shibasaki, H. Yokota, S. Yamada, T. Shinozuka, S. Iwasaki, K. Kotajima, T. Numao, and S. Itagaki

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle decay, Neutron emission, Beta (velocity), Atomic physics, Beta decay, Radioactive decay, Spectral line, Fermi Gamma-ray Space Telescope
Abstract

A superallowed Fermi ..beta.. transition (J/sup ..pi../ = 0/sup +/, T = 1) from /sup 62/Ga (A = 4n + 2) has been identified. The measured half-life and ..beta.. ray end point energy are T/sub 1/2/ = 116.4 +- 1.5 msec and E/sub betamax/ = 8.3 +- 0.3 MeV, respectively. The Ft value for the transition has been evaluated with the measured half-life and estimated ..beta.. ray end point energy from a phenomenological analysis of the Coulomb displacement energies of isobaric analog states. The obtained value is Ft = ft (1 +delta/sub R/)(1 - delta/sub C/) = 3103 +- 44 sec which turns out to be 0.6% larger than that expected for such 0/sup +/-0/sup +/ superallowed ..beta.. transitions.

Published
1978

41. Measurements of Cross Sections for Pion Absorption by Nuclei

Author

K. Masutani, K. Nakai, T. Kobayashi, Tatsuo Shibata, T. Numao, and J. Chiba

Subjects
Physics, Nuclear reaction, Light nucleus, Range (particle radiation), Aluminium-27, Nuclear Theory, General Physics and Astronomy, Nuclear physics, Pion, Absorption (logic), Isotopes of gold, Atomic physics, Nuclear Experiment, Energy (signal processing)
Abstract

Cross sections for true absorption by nuclei (Al, Ti, Cu, Sn, Au) of pions (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$) in the energy range from 20 to 280 MeV were measured by a new method of detecting nuclear $\ensuremath{\gamma}$ rays following the reaction. The incident-energy dependence of the cross sections in the low-energy region (${T}_{\ensuremath{\pi}}l50$ MeV) was well reproduced by an optical-model calculation, while the higher-energy part seems to indicate complex mechanisms of pion absorption.

Published
1980

42. Search for Massive Neutrinos in the Decayπ→eν

Author

Douglas Bryman, B. Olaniyi, A. Olin, J. M. Poutissou, J. A. Macdonald, Dixit, T. Numao, and R. Dubois

Subjects
Physics, Particle physics, Branching fraction, High Energy Physics::Phenomenology, Pi, General Physics and Astronomy, High Energy Physics::Experiment, Neutrino, Intensity (heat transfer)
Abstract

The positron spectrum from the decay ${\ensuremath{\pi}}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e}$ has been examined for evidence of peaks arising from an admixture in the ${\ensuremath{\nu}}_{e}$ weak eigenstate of massive neutrinos. Limits on the intensity of such peaks, together with the measured $\ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu}$ branching ratio, have been used to derive constraints on the neutrino mixing parameters over the range $4 \mathrm{MeV}lm(\ensuremath{\nu})l135 \mathrm{MeV}$.

Published
1983

43. New Measurement of theπ→eνBranching Ratio

Author

D. Berghofer, T. Numao, A. Olin, Douglas Bryman, R. Dubois, J. A. Macdonald, M. S. Dixit, B. Olaniyi, J. M. Poutissou, and B. C. Robertson

Subjects
Physics, Nuclear physics, Particle decay, Antiparticle, Pion, Positron, Meson, Branching fraction, Hadron, Pi, Analytical chemistry, General Physics and Astronomy
Abstract

A new measurement of the ..pi -->..e..nu.. branching ratio yields GAMMA(..pi -->..e..nu..+..pi -->..e..nu gamma..)/GAMMA(..pi --> mu nu..+..pi --> mu nu.. ..gamma..) = (1.218 +- 0.014) x 10/sup -4./ The measured value is in good agreement with the standard-model prediction incorporating electron-muon universality.

Published
1983

44. Search forμ-econversion in Ti

Author

P. Schlatter, M. J. Leitch, M. D. Hasinoff, J. A. Macdonald, Navon I I, K. Gotow, J. Spuller, J.-M. Poutissou, Douglas Bryman, M. S. Dixit, M. Blecher, A.L. Carter, Georges Azuelos, T. Numao, E. T. H. Clifford, P. Depommier, Herbert L. Anderson, R. A. Burnham, H. Mes, Jean-Pierre Martin, C. K. Hargrove, S. C. Wright, and R. Poutissou

Subjects
Physics, Particle physics, Crystallography, Muon, Branching fraction, Particle model, High Energy Physics::Phenomenology, General Physics and Astronomy, Elementary particle
Abstract

A search has been performed for the lepton-flavor-nonconserving reaction ${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$+Ti\ensuremath{\rightarrow}${e}^{\mathrm{\ensuremath{-}}}$+Ti using a time-projection chamber. No candidate events were observed, resulting in a limit of \ensuremath{\Gamma}(${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$+Ti\ensuremath{\rightarrow}${e}^{\mathrm{\ensuremath{-}}}$+Ti) / \ensuremath{\Gamma}(${\ensuremath{\mu}}^{\mathrm{\ensuremath{-}}}$+Ti\ensuremath{\rightarrow}capture) 1.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}11}$ (90% C.L.) for this reaction relative to ordinary muon capture.

Published
1985

45. Measurement of thepi→eνbranching ratio

Author

A. Olin, B. Olaniyi, J. M. Poutissou, J. A. Macdonald, T. Numao, M. S. Dixit, R. Dubois, and Douglas Bryman

Subjects
Physics, Nuclear physics, Particle decay, Pion, Meson, Branching fraction, Electroweak interaction, Hadron, Analytical chemistry, Elementary particle, Lepton
Abstract

A measurement of the ..pi -->..e..nu.. branching ratio using a NaI(Tl) spectrometer yields a value GAMMA((..pi -->..e..nu..)+(..pi -->..e..nu gamma..))/ GAMMA((..pi --> mu nu..)+(..pi --> mu nu gamma..)) = (1. 218 +- 0.014) x 10/sup -4/. The result is consistent with expectations of the standard electroweak theory incorporating electron-muon universality.

Published
1986

46. Constraints on Massive Neutrinos inπ→eνDecay

Author

A. Olin, P. Kitching, T. Numao, Georges Azuelos, Dave Britton, P. Schlatter, Douglas Bryman, E. T. H. Clifford, J. A. Macdonald, M. S. Dixit, B. Olaniyi, and J. M. Poutissou

Subjects
Massless particle, Physics, Nuclear physics, Particle decay, Particle physics, Pion, Meson, Antimatter, General Physics and Astronomy, High Energy Physics::Experiment, Decay chain, Neutrino, Lepton
Abstract

A search has been carried out for the production of neutrinos in the mass range 60 to 130 MeV coupling to the electron in the decay ..pi../sup +/..-->..e/sup +/..nu... The dominant background from the ..pi..-..mu..-e decay chain has been suppressed by use of a new technique leading to more than an order of magnitude greater sensitivity than achieved previously.

Published
1986

47. Searches for Majoron production and other processes associated withπ→eνdecay

Author

P. Kitching, Salahuddin Ahmad, Douglas Bryman, J. A. Macdonald, A. Olin, J. Summhammer, J. M. Poutissou, M. S. Dixit, T. Numao, Dave Britton, Y. Kuno, C. E. Picciotto, and E. T. H. Clifford

Subjects
Nuclear physics, Physics, Particle decay, Antiparticle, Particle physics, Pion, Meson, Branching fraction, High Energy Physics::Phenomenology, Hadron, High Energy Physics::Experiment, Particle identification, Majoron
Abstract

Data from a new study of the decay ..pi -->..e..nu.. are used to place bounds on Majoron-neutrino couplings and to obtain inclusive branching-ratio limits for ..pi -->..e..nu..M, where M is a new particle with a mass in the range 0 to 125 MeV. A limit for the process ..pi../sup +/..-->..e/sup +/..nu nu..nu-bar is also obtained.

Published
1988

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