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Phys. Rev. Lett. 100, 221803 (2008) [5 pages]

Precision Measurement of Neutrino Oscillation Parameters with KamLAND

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S. Abe et al. The KamLAND Collaboration
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See Also: Publisher's Note, Publisher's Note

Received 29 January 2008; published 5 June 2008; publisher error corrected 10 December 2008

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 2.44×1032  proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor ν̅ 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 Δm212=7.58-0.13+0.14(stat)-0.15+0.15(syst)×10-5  eV2 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+0.21×10-5  eV2 and tan⁡2θ12=0.47-0.05+0.06.

© 2008 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.100.221803
DOI:
10.1103/PhysRevLett.100.221803
PACS:
14.60.Pq, 26.65.+t, 28.50.Hw, 91.35.−x

See Also

Publisher's Note: S. Abe et al. KamLAND Collaboration, Publisher’s Note: Precision Measurement of Neutrino Oscillation Parameters with KamLAND [Phys. Rev. Lett. 100, 221803 (2008)], Phys. Rev. Lett. 101, 119904 (2008).

Publisher's Note: S. Abe et al. KamLAND Collaboration, Publisher’s Note: Precision Measurement of Neutrino Oscillation Parameters with KamLAND [Phys. Rev. Lett. 100, 221803 (2008)], Phys. Rev. Lett. 101, 259901 (2008).