Precision measurement of neutrino oscillation parameters with KamLAND
Document Type
Article
Publication Date
6-5-2008
Abstract
The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Δm212 and stringent constraints on θ12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44×1032protonyr due to longer livetime and an enlarged fiducial volume. An undistorted reactor ν̄e 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 Δm212=7.58-0.13+0.14(stat)-0.15+0.15(syst)×10-5eV2 and tan 2θ12=0.56-0.07+0.10(stat)-0.06+0.10(syst). Local Δχ2 minima at higher and lower Δm212 are disfavored at >4σ. Combining with solar neutrino data, we obtain Δm212=7.59-0.21+0.21×10-5eV2 and tan 2θ12=0.47-0.05+0.06. © 2008 The American Physical Society.
Recommended Citation
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.; and Keefer, G., "Precision measurement of neutrino oscillation parameters with KamLAND" (2008). Regis University Faculty Publications (comprehensive list). 986.
https://epublications.regis.edu/facultypubs/986