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Precision measurement of neutrino oscillation parameters with KamLAND (2008) |
- Abe, S.,
- Ebihara, T.,
- Enomoto, S.,
- Furuno, K.,
- Gando, Y.,
- Ichimura, K.,
- Ikeda, H.,
- Inoue, K.,
- Kibe, Y.,
- Kishimoto, Y.,
- Koga, M.,
- Kozlov, A.,
- Minekawa, Y.,
- Mitsui, T.,
- Nakajima, K.,
- Nakajima, K.,
- Nakamura, K.,
- Nakamura, M.,
- Owada, K.,
- Shimizu, I.,
- Shimizu, Y.,
- Shirai, J.,
- Suekane, F.,
- Suzuki, A.,
- Takemoto, Y.,
- Tamae, K.,
- Terashima, A.,
- Watanabe, H.,
- Yonezawa, E.,
- Yoshida, S.,
- Busenitz, J.,
- Classen, T.,
- Grant, C.,
- Keefer, G.,
- Leonard, D. S.,
- McKee, D.,
- Piepke, A.,
- Decowski, M. P.,
- Detwiler, J. A.,
- Freedman, S. J.,
- Fujikawa, B. K.,
- Gray, F.,
- Guardincerri, E.,
- Hsu, L.,
- Kadel, R.,
- Lendvai, C.,
- Murayama, H.,
- O’Donnell, T.,
- Steiner, H. M.,
- Winslow, L. A.,
- Dwyer, D. A.,
- Jillings, C.,
- Mauger, C.,
- McKeown, R. D.,
- Vogel, P.,
- Zhang, Z.,
- Berger, B. E.,
- Lane, C. E.,
- Maricic, J.,
- Miletic, T.,
- Batygov, M.,
- Learned, J. G.,
- Matsuno, S.,
- Pakvasa, S.,
- Foster, J.,
- Horton-Smith, G. A.,
- Tang, A.,
- Dazeley, S.,
- Downum, K. E.,
- Gratta, G.,
- Tolich, K.,
- Bugg, W.,
- Efremenko, Y.,
- Kamyshkov, Y.,
- Perevozchikov, O.,
- Karwowski, H. J.,
- Markoff, D. M.,
- Tornow, W.,
- Heeger, K. M.,
- Piquemal, F.
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Abstract |
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The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Δm2 21 and stringent constraints on θ12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2:44 x 10 32 proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor ∇e energy spectrum is now rejected at >5σ. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Δm2 21= 7.58+0.14-0.13(stat)+0.15-0.15(syst)x10-5 eV2 and tan 2θ 2=0.56+0.10-0.07(stat)+0.10-0.06(syst). Local Δχ2 minima at higher and lower Δm2 21 are disfavored at >4σ. Combining with solar neutrino data, we obtain Δm2 21 7.59+0.21-0.21 X 10-5 eV2 and tan2θ12=0.47+0.06-0.05. |
Publication details |
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