Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.

Published

Journal Article

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 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 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 nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.

Full Text

Duke Authors

Cited Authors

  • Araki, T; Eguchi, K; Enomoto, S; Furuno, K; Ichimura, K; Ikeda, H; Inoue, K; Ishihara, K; Iwamoto, T; Kawashima, T; Kishimoto, Y; Koga, M; Koseki, Y; Maeda, T; Mitsui, T; Motoki, M; Nakajima, K; Ogawa, H; Owada, K; Ricol, J-S; Shimizu, I; Shirai, J; Suekane, F; Suzuki, A; Tada, K; Tajima, O; Tamae, K; Tsuda, Y; Watanabe, H; Busenitz, J; Classen, T; Djurcic, Z; Keefer, G; McKinny, K; Mei, D-M; Piepke, A; Yakushev, E; Berger, BE; Chan, YD; Decowski, MP; Dwyer, DA; Freedman, SJ; Fu, Y; Fujikawa, BK; Goldman, J; Gray, F; Heeger, KM; Lesko, KT; Luk, K-B; Murayama, H; Poon, AWP; Steiner, HM; Winslow, LA; Horton-Smith, GA; Mauger, C; McKeown, RD; Vogel, P; Lane, CE; Miletic, T; Gorham, PW; Guillian, G; Learned, JG; Maricic, J; Matsuno, S; Pakvasa, S; Dazeley, S; Hatakeyama, S; Rojas, A; Svoboda, R; Dieterle, BD; Detwiler, J; Gratta, G; Ishii, K; Tolich, N; Uchida, Y; Batygov, M; Bugg, W; Efremenko, Y; Kamyshkov, Y; Kozlov, A; Nakamura, Y; Gould, CR; Karwowski, HJ; Markoff, DM; Messimore, JA; Nakamura, K; Rohm, RM; Tornow, W; Wendell, R; Young, AR; Chen, M-J; Wang, Y-F; Piquemal, F; KamLAND Collaboration,

Published Date

  • March 2005

Published In

Volume / Issue

  • 94 / 8

Start / End Page

  • 081801 -

PubMed ID

  • 15783875

Pubmed Central ID

  • 15783875

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.94.081801

Language

  • eng