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S. Hayashida

Bio: S. Hayashida is an academic researcher from Tohoku University. The author has contributed to research in topics: Neutrino & Electron neutrino. The author has an hindex of 9, co-authored 20 publications receiving 1284 citations.

Papers
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Journal ArticleDOI
TL;DR: An improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment is presented and a significant reduction of the xenon-loaded liquid scintillator contaminant identified in previous searches is achieved.
Abstract: We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26} yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

1,055 citations

Journal ArticleDOI
TL;DR: This corrects the article DOI: 10.1103/PhysRevLett.117.082503 to reflect that the paper was originally published in Physical Review Letters, not RevLett, rather than Science.
Abstract: Author(s): Gando, A; Gando, Y; Hachiya, T; Hayashi, A; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Karino, Y; Koga, M; Matsuda, S; Mitsui, T; Nakamura, K; Obara, S; Oura, T; Ozaki, H; Shimizu, I; Shirahata, Y; Shirai, J; Suzuki, A; Takai, T; Tamae, K; Teraoka, Y; Ueshima, K; Watanabe, H; Kozlov, A; Takemoto, Y; Yoshida, S; Fushimi, K; Banks, TI; Berger, BE; Fujikawa, BK; O'Donnell, T; Winslow, LA; Efremenko, Y; Karwowski, HJ; Markoff, DM; Tornow, W; Detwiler, JA; Enomoto, S; Decowski, MP; KamLAND-Zen Collaboration | Abstract: This corrects the article DOI: 10.1103/PhysRevLett.117.082503.

192 citations

Journal ArticleDOI
TL;DR: The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in this paper using a xenonloaded liquid scintillator.
Abstract: The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26} yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

52 citations

Journal ArticleDOI
TL;DR: In this article, the first experimental lower half-life limits for the transitions to the 0 1 + state of 136Xe for 0 β β and 2 β β β decay were reported.

51 citations

Journal ArticleDOI
TL;DR: In this paper, Asakura et al. showed that the kiloton-scale liquid scintillator detector KamLAND can detect pre-supernova neutrinos from a star with a mass of 25 M ǫ at a distance less than 690 pc with 3σ significance before the supernova.
Abstract: Author(s): The KamLAND Collaboration; Asakura, K; Gando, A; Gando, Y; Hachiya, T; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Ishikawa, T; Ishio, S; Koga, M; Matsuda, S; Mitsui, T; Motoki, D; Nakamura, K; Obara, S; Oura, T; Shimizu, I; Shirahata, Y; Shirai, J; Suzuki, A; Tachibana, H; Tamae, K; Ueshima, K; Watanabe, H; Xu, BD; Kozlov, A; Takemoto, Y; Yoshida, S; Fushimi, K; Piepke, A; Banks, TI; Berger, BE; Fujikawa, BK; O'Donnell, T; Learned, JG; Maricic, J; Matsuno, S; Sakai, M; Winslow, LA; Efremenko, Y; Karwowski, HJ; Markoff, DM; Tornow, W; Detwiler, JA; Enomoto, S; Decowski, MP | Abstract: In the late stages of nuclear burning for massive stars (M g 8 Mȯ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 Mȯ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

46 citations


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TL;DR: The first direct detection of gravitational waves and the first observation of a binary black hole merger were reported in this paper, with a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ.
Abstract: On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160) Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

4,375 citations

Journal ArticleDOI
TL;DR: In this paper, a global analysis of the neutrino oscillation data available as of fall 2018 in the framework of three massive mixed neutrinos with the goal at determining the ranges of allowed values for the six relevant parameters.
Abstract: We present the results of a global analysis of the neutrino oscillation data available as of fall 2018 in the framework of three massive mixed neutrinos with the goal at determining the ranges of allowed values for the six relevant parameters. We describe the complementarity and quantify the tensions among the results of the different data samples contributing to the determination of each parameter. We also show how those vary when combining our global likelihood with the χ2 map provided by Super-Kamiokande for their atmospheric neutrino data analysis in the same framework. The best fit of the analysis is for the normal mass ordering with inverted ordering being disfavoured with a Δχ2 = 4.7 (9.3) without (with) SK-atm. We find a preference for the second octant of θ23, disfavouring the first octant with Δχ2 = 4.4 (6.0) without (with) SK-atm. The best fit for the complex phase is δCP = 215° with CP conservation being allowed at Δχ2 = 1.5 (1.8). As a byproduct we quantify the correlated ranges for the laboratory observables sensitive to the absolute neutrino mass scale in beta decay, $$ {m}_{ u_e} $$ , and neutrino-less double beta decay, mee, and the total mass of the neutrinos, Σ, which is most relevant in Cosmology.

860 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, M. R. Abernathy3  +1135 moreInstitutions (139)
TL;DR: In this article, the authors present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves.
Abstract: We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– 20 deg2 requires at least three detectors of sensitivity within a factor of ∼2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

804 citations

Journal ArticleDOI
Jelle Aalbers1, F. Agostini2, M. Alfonsi3, F. D. Amaro4, Claude Amsler5, Elena Aprile6, Lior Arazi7, F. Arneodo8, P. Barrow9, Laura Baudis1, Laura Baudis9, M. L. Benabderrahmane8, T. Berger10, B. Beskers3, Amos Breskin7, P. A. Breur1, April S. Brown1, Ethan Brown10, S. Bruenner11, Giacomo Bruno, Ran Budnik7, Lukas Bütikofer5, J. Calvén12, João Cardoso4, D. Cichon11, D. Coderre5, Auke-Pieter Colijn1, Jan Conrad12, Jean-Pierre Cussonneau13, M. P. Decowski1, Sara Diglio13, Guido Drexlin14, Ehud Duchovni7, E. Erdal7, G. Eurin11, A. D. Ferella12, A. Fieguth15, W. Fulgione, A. Gallo Rosso, P. Di Gangi2, A. Di Giovanni8, Michelle Galloway9, M. Garbini2, C. Geis3, F. Glueck14, L. Grandi16, Z. Greene6, C. Grignon3, C. Hasterok11, Volker Hannen15, E. Hogenbirk1, J. Howlett6, D. Hilk14, C. Hils3, A. James9, B. Kaminsky5, Shingo Kazama9, Benjamin Kilminster9, A. Kish9, Lawrence M. Krauss17, H. Landsman7, R. F. Lang18, Qing Lin6, F. L. Linde1, Sebastian Lindemann11, Manfred Lindner11, J. A. M. Lopes4, Marrodan T. Undagoitia11, Julien Masbou13, F. V. Massoli2, D. Mayani9, M. Messina6, K. Micheneau13, A. Molinario, K. Morå12, E. Morteau13, M. Murra15, J. Naganoma19, Jayden L. Newstead17, Kaixuan Ni20, Uwe Oberlack3, P. Pakarha9, Bart Pelssers12, P. de Perio6, R. Persiani13, F. Piastra9, M.-C. Piro10, G. Plante6, L. Rauch11, S. Reichard18, A. Rizzo6, N. Rupp11, J.M.F. dos Santos4, G. Sartorelli2, M. Scheibelhut3, S. Schindler3, Marc Schumann5, Marc Schumann21, Jochen Schreiner11, L. Scotto Lavina13, M. Selvi2, P. Shagin19, Miguel Silva4, Hardy Simgen11, P. Sissol3, M. von Sivers5, D. Thers13, J. Thurn22, A. Tiseni1, Roberto Trotta23, C. Tunnell1, Kathrin Valerius14, M. Vargas15, Hongwei Wang24, Yuehuan Wei9, Ch. Weinheimer15, T. Wester22, J. Wulf9, Yanxi Zhang6, T. Zhu9, Kai Zuber22 
TL;DR: DARk matter WImp search with liquid xenoN (DARWIN) as mentioned in this paper is an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core.
Abstract: DARk matter WImp search with liquid xenoN (DARWIN(2)) will be an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core. Its primary g ...

553 citations

Journal ArticleDOI
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