Showing papers by "Shoji Yamamoto published in 2015"
University of Tokyo1, Boston University2, Brookhaven National Laboratory3, University of California, Irvine4, California State University, Dominguez Hills5, Chonnam National University6, Duke University7, George Mason University8, Gifu University9, Indiana University10, Kobe University11, Kyoto University12, Los Alamos National Laboratory13, Louisiana State University14, University of Maryland, College Park15, University of Minnesota16, Miyagi University of Education17, Nagoya University18, Stony Brook University19, Niigata University20, Okayama University21, Osaka University22, Seoul National University23, Shizuoka University24, Sungkyunkwan University25, Tohoku University26, Tokai University27, Tokyo Institute of Technology28, Tsinghua University29, University of Warsaw30, University of Washington31
TL;DR: A search for neutrino-antineutron (n-n¯) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or 2.45×1034 neutron-year exposure data.
Abstract: Author(s): Abe, K; Hayato, Y; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Obayashi, Y; Ogawa, H; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Watanabe, H; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nakayama, S; Nishino, H; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Herfurth, A; Kearns, E; Likhoded, S; Litos, M; Raaf, JL; Stone, JL; Sulak, LR; Wang, W; Goldhaber, M; Casper, D; Cravens, JP; Dunmore, J; Griskevich, J; Kropp, WR; Liu, DW; Mine, S; Regis, C; Smy, MB; Sobel, HW; Vagins, MR; Ganezer, KS; Hartfiel, B; Hill, J; Keig, WE; Jang, JS; Jeoung, IS; Kim, JY; Lim, IT; Scholberg, K; Tanimoto, N; Walter, CW; Wendell, R; Ellsworth, RW; Tasaka, S; Guillian, G; Learned, JG; Matsuno, S; Messier, MD; Ichikawa, AK; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Nitta, K; Oyama, Y; Suzuki, AT; Hasegawa, M; Maesaka, H | Abstract: A search for neutron-antineutron (n-n¯) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or 2.45×1034 neutron-year exposure data. This process violates both baryon and baryon minus lepton numbers by an absolute value of two units and is predicted by a large class of hypothetical models where the seesaw mechanism is incorporated to explain the observed tiny neutrino masses and the matter-antimatter asymmetry in the Universe. No evidence for n-n¯ oscillation was found; the lower limit of the lifetime for neutrons bound in O16, in an analysis that included all of the significant sources of experimental uncertainties, was determined to be 1.9×1032years at the 90% confidence level. The corresponding lower limit for the oscillation time of free neutrons was calculated to be 2.7×108s using a theoretical value of the nuclear suppression factor of 0.517×1023s-1 and its uncertainty.
103 citations
Graduate University for Advanced Studies1, Kyushu University2, General Atomics3, Japan Atomic Energy Agency4, Max Planck Society5, Kyoto University6, European Atomic Energy Community7, Nagoya University8, Princeton Plasma Physics Laboratory9, University of Tokyo10, Tottori University11, Shizuoka University12, University of Tsukuba13, Kyoto Institute of Technology14, Osaka University15, Tohoku University16
TL;DR: Kaneko et al. as mentioned in this paper reviewed the progress in the understanding of the physics and concurrent parameter extension in the large helical device since the last IAEA-FEC, in 2012.
Abstract: The progress in the understanding of the physics and the concurrent parameter extension in the large helical device since the last IAEA-FEC, in 2012 (Kaneko O et al 2013 Nucl. Fusion 53 095024), is reviewed. Plasma with high ion and electron temperatures (Ti(0) ~ Te(0) ~ 6 keV) with simultaneous ion and electron internal transport barriers is obtained by controlling recycling and heating deposition. A sign flip of the nondiffusive term of impurity/momentum transport (residual stress and convection flow) is observed, which is associated with the formation of a transport barrier. The impact of the topology of three-dimensional magnetic fields (stochastic magnetic fields and magnetic islands) on heat momentum, particle/impurity transport and magnetohydrodynamic stability is also discussed. In the steady state operation, a 48 min discharge with a line-averaged electron density of 1 × 1019 m−3 and with high electron and ion temperatures (Ti(0) ~ Te(0) ~ 2 keV), resulting in 3.36 GJ of input energy, is achieved.
14 citations