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Author

T. Mitsui

Other affiliations: Kobe University, University of Tokyo
Bio: T. Mitsui is an academic researcher from Tohoku University. The author has contributed to research in topics: Neutrino & Cosmic ray. The author has an hindex of 32, co-authored 80 publications receiving 8574 citations. Previous affiliations of T. Mitsui include Kobe University & University of Tokyo.


Papers
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Journal ArticleDOI
K. Eguchi1, Sanshiro Enomoto1, K. Furuno1, J. Goldman1, H. Hanada1, H. Ikeda, Kiyohiro Ikeda1, Kunio Inoue, K. Ishihara1, W. Itoh1, T. Iwamoto1, Tomoya Kawaguchi1, T. Kawashima1, H. Kinoshita1, Yasuhiro Kishimoto, M. Koga, Y. Koseki1, T. Maeda1, T. Mitsui, M. Motoki, K. Nakajima1, M. Nakajima1, T. Nakajima1, Hiroshi Ogawa1, K. Owada1, T. Sakabe1, I. Shimizu, J. Shirai1, F. Suekane, A. Suzuki1, K. Tada1, Osamu Tajima1, T. Takayama1, K. Tamae1, Hideki Watanabe, J. Busenitz2, Z. Djurcic2, K. McKinny2, Dongming Mei2, A. Piepke2, E. Yakushev2, B. E. Berger3, Y. D. Chan3, M. P. Decowski3, D. A. Dwyer3, Stuart J. Freedman3, Y. Fu3, B. K. Fujikawa3, K. M. Heeger3, K. T. Lesko3, K. B. Luk3, Hitoshi Murayama3, D. R. Nygren3, C. E. Okada3, A. W. P. Poon3, H. M. Steiner3, Lindley Winslow3, G. A. Horton-Smith4, R. D. McKeown4, J. Ritter4, B. Tipton4, Petr Vogel4, C. E. Lane5, T. Miletic5, Peter Gorham, G. Guillian, John G. Learned, J. Maricic, S. Matsuno, Sandip Pakvasa, S. Dazeley6, S. Hatakeyama6, M. Murakami6, R. Svoboda6, B. D. Dieterle7, M. DiMauro7, J. A. Detwiler8, Giorgio Gratta8, K. Ishii8, N. Tolich8, Y. Uchida8, M. Batygov9, W. M. Bugg9, H. O. Cohn9, Yuri Efremenko9, Yuri Kamyshkov9, A. Kozlov9, Y. Nakamura9, L. De Braeckeleer10, L. De Braeckeleer11, C. R. Gould10, C. R. Gould11, Hugon J Karwowski10, Hugon J Karwowski11, D. M. Markoff10, D. M. Markoff11, J. A. Messimore11, J. A. Messimore10, Koji Nakamura10, Koji Nakamura11, Ryan Rohm11, Ryan Rohm10, Werner Tornow10, Werner Tornow11, Albert Young11, Albert Young10, Y. F. Wang 
TL;DR: In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrinos problem except for the "large mixing angle" region are excluded.
Abstract: KamLAND has measured the flux of ν _e’s from distant nuclear reactors. We find fewer ν _e events than expected from standard assumptions about ν _e propagation at the 99.95% C.L. In a 162 ton·yr exposure the ratio of the observed inverse β-decay events to the expected number without ν _e disappearance is 0.611±0.085(stat)±0.041(syst) for ν _e energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the “large mixing angle” region are excluded.

2,108 citations

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
T. Araki1, K. Eguchi1, Sanshiro Enomoto1, K. Furuno1, Koichi Ichimura, H. Ikeda, Kunio Inoue, K. Ishihara2, K. Ishihara1, T. Iwamoto1, T. Iwamoto2, T. Kawashima1, Yasuhiro Kishimoto, M. Koga, Y. Koseki1, T. Maeda1, T. Mitsui, M. Motoki, K. Nakajima1, Hiroshi Ogawa1, K. Owada1, J. S. Ricol1, I. Shimizu, J. Shirai, F. Suekane, A. Suzuki1, K. Tada1, Osamu Tajima1, K. Tamae, Y. Tsuda1, Hiroko Watanabe, J. Busenitz3, T. Classen3, Z. Djurcic3, G. Keefer3, K. McKinny3, Dongming Mei3, Dongming Mei4, A. Piepke3, E. Yakushev3, B. E. Berger5, B. E. Berger6, Y. D. Chan6, Y. D. Chan5, M. P. Decowski5, M. P. Decowski6, D. A. Dwyer5, D. A. Dwyer6, Stuart J. Freedman5, Stuart J. Freedman6, Y. Fu6, Y. Fu5, B. K. Fujikawa5, B. K. Fujikawa6, J. Goldman5, J. Goldman6, Frederick Gray6, Frederick Gray5, K. M. Heeger6, K. M. Heeger5, K. T. Lesko6, K. T. Lesko5, Kam Biu Luk6, Kam Biu Luk5, Hitoshi Murayama5, Hitoshi Murayama6, A. W. P. Poon5, A. W. P. Poon6, H. M. Steiner6, H. M. Steiner5, Lindley Winslow6, Lindley Winslow5, G. A. Horton-Smith7, G. A. Horton-Smith8, C. Mauger8, R. D. McKeown8, Petr Vogel8, C. E. Lane9, T. Miletic9, Peter Gorham, G. Guillian, John G. Learned, J. Maricic, S. Matsuno, Sandip Pakvasa, S. Dazeley10, S. Hatakeyama10, A. Rojas10, Robert Svoboda10, B. D. Dieterle11, J. A. Detwiler12, Giorgio Gratta12, K. Ishii12, N. Tolich12, Y. Uchida12, Y. Uchida13, M. Batygov14, W. M. Bugg14, Yuri Efremenko14, Y. Kamyshkov14, A. Kozlov14, Y. Nakamura14, C. R. Gould15, C. R. Gould16, Hugon J Karwowski16, Hugon J Karwowski15, D. M. Markoff15, D. M. Markoff16, J. A. Messimore16, J. A. Messimore15, Koji Nakamura15, Koji Nakamura16, Ryan Rohm16, Ryan Rohm15, Werner Tornow16, Werner Tornow15, R. Wendell16, R. Wendell15, Albert Young15, Albert Young16, M. J. Chen, Y. F. Wang, F. Piquemal17 
TL;DR: In this article, a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos is presented, where the observed energy spectrum disagrees with the expected spectral shape.
Abstract: We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 [overline nu ]e candidate events with energies above 3.4 MeV compared to 365.2±23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8±7.3 expected background events, the statistical significance for reactor [overline nu ]e disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from [overline nu ]e oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam2=7.9 -0.5 +0.6 ×10-5 eV2. A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam2=7.9 -0.5 +0.6 ×10-5 eV2 and tan2theta=0.40 -0.07 +0.10 , the most precise determination to date.

992 citations

Journal ArticleDOI
TL;DR: The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations.
Abstract: We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of Xe136. We obtain a lower limit for the neutrinoless double-beta decay half-life of T0ν1/2>1.9×1025 yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T0ν1/2>3.4×1025 yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of ⟨mββ⟩<(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in Ge76, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

433 citations

Journal ArticleDOI
28 Jul 2005-Nature
TL;DR: Although the present data have limited statistical power, they nevertheless provide by direct means an upper limit for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.
Abstract: The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of ^(238)U and ^(232)Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

393 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: In this article, the Wilkinson Microwave Anisotropy Probe (WMAP) 5-year data were used to constrain the physics of cosmic inflation via Gaussianity, adiabaticity, the power spectrum of primordial fluctuations, gravitational waves, and spatial curvature.
Abstract: The Wilkinson Microwave Anisotropy Probe (WMAP) 5-year data provide stringent limits on deviations from the minimal, six-parameter Λ cold dark matter model. We report these limits and use them to constrain the physics of cosmic inflation via Gaussianity, adiabaticity, the power spectrum of primordial fluctuations, gravitational waves, and spatial curvature. We also constrain models of dark energy via its equation of state, parity-violating interaction, and neutrino properties, such as mass and the number of species. We detect no convincing deviations from the minimal model. The six parameters and the corresponding 68% uncertainties, derived from the WMAP data combined with the distance measurements from the Type Ia supernovae (SN) and the Baryon Acoustic Oscillations (BAO) in the distribution of galaxies, are: Ω b h 2 = 0.02267+0.00058 –0.00059, Ω c h 2 = 0.1131 ± 0.0034, ΩΛ = 0.726 ± 0.015, ns = 0.960 ± 0.013, τ = 0.084 ± 0.016, and at k = 0.002 Mpc-1. From these, we derive σ8 = 0.812 ± 0.026, H 0 = 70.5 ± 1.3 km s-1 Mpc–1, Ω b = 0.0456 ± 0.0015, Ω c = 0.228 ± 0.013, Ω m h 2 = 0.1358+0.0037 –0.0036, z reion = 10.9 ± 1.4, and t 0 = 13.72 ± 0.12 Gyr. With the WMAP data combined with BAO and SN, we find the limit on the tensor-to-scalar ratio of r 1 is disfavored even when gravitational waves are included, which constrains the models of inflation that can produce significant gravitational waves, such as chaotic or power-law inflation models, or a blue spectrum, such as hybrid inflation models. We obtain tight, simultaneous limits on the (constant) equation of state of dark energy and the spatial curvature of the universe: –0.14 < 1 + w < 0.12(95%CL) and –0.0179 < Ω k < 0.0081(95%CL). We provide a set of WMAP distance priors, to test a variety of dark energy models with spatial curvature. We test a time-dependent w with a present value constrained as –0.33 < 1 + w 0 < 0.21 (95% CL). Temperature and dark matter fluctuations are found to obey the adiabatic relation to within 8.9% and 2.1% for the axion-type and curvaton-type dark matter, respectively. The power spectra of TB and EB correlations constrain a parity-violating interaction, which rotates the polarization angle and converts E to B. The polarization angle could not be rotated more than –59 < Δα < 24 (95% CL) between the decoupling and the present epoch. We find the limit on the total mass of massive neutrinos of ∑m ν < 0.67 eV(95%CL), which is free from the uncertainty in the normalization of the large-scale structure data. The number of relativistic degrees of freedom (dof), expressed in units of the effective number of neutrino species, is constrained as N eff = 4.4 ± 1.5 (68%), consistent with the standard value of 3.04. Finally, quantitative limits on physically-motivated primordial non-Gaussianity parameters are –9 < f local NL < 111 (95% CL) and –151 < f equil NL < 253 (95% CL) for the local and equilateral models, respectively.

5,904 citations

Journal ArticleDOI
TL;DR: The current status of particle dark matter, including experimental evidence and theoretical motivations, including direct and indirect detection techniques, is discussed in this paper. But the authors focus on neutralinos in models of supersymmetry and Kaluza-Klein dark matter in universal extra dimensions.

4,614 citations

Journal Article
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