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

  title={Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.},
  author={T Araki and K Eguchi and S Enomoto and K Furuno and K Ichimura and H Ikeda and K Inoue and K Ishihara and T Iwamoto and T Kawashima and Y Kishimoto and M Koga and Y Koseki and T Maeda and T Mitsui and M Motoki and K Nakajima and H Ogawa and K Owada and J-S Ricol and I Shimizu and J Shirai and Fumihiko Suekane and A Suzuki and K Tada and O Tajima and K Tamae and Y Tsuda and H Watanabe and Jerome K. Busenitz and T Classen and Z. Djurcic and G Keefer and K. McKinny and D. Mei and A Piepke and E Yakushev and B E Berger and Y.-C. Chan and M. P. Decowski and D A Dwyer and S J Freedman and Y Fu and Bruce K Fujikawa and J Goldman and F Gray and Karsten Miklas Heeger and Kevin T. Lesko and K. B. Luk and H Murayama and A W P Poon and H M Steiner and Luke A. Winslow and Glenn A. Horton-Smith and C Mauger and R. D. Mckeown and P Vogel and C E Lane and T Miletic and Peter W. Gorham and G. Guillian and John G. Learned and Jelena Mari{\vc}i{\'c} and S Matsuno and Sandip Pakvasa and Steven Dazeley and S Hatakeyama and A Rojas and R Svoboda and Byron D. Dieterle and J Detwiler and Giorgio Gratta and K Ishii and Nikolai Tolich and Y Uchida and M. Batygov and W. Bugg and Y Efremenko and Yuri Kamyshkov and A Kozlov and Y Nakamura and C R Gould and Hugon Karwowski and Diane M. Markoff and J. A. Messimore and K Nakamura and Ryan M. Rohm and Werner Tornow and R Wendell and A R Young and M-J Chen and Y-F Wang and Françoise Piquemal},
  journal={Physical review letters},
  volume={94 8},
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… CONTINUE READING