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First results from KamLAND

First results from KamLAND. M.Motoki  ( Tohoku University) For the KamLAND Collaboration. Neutrino Oscillation. SuperK day night, SuperK energy spectrum  LMA+LOW. LMA. SNO NC; n e + n m + n t. SMA. Flavor transition day/night LMA. LOW. KamLAND; Artificial neutrino sources

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First results from KamLAND

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  1. First results from KamLAND M.Motoki (Tohoku University) For the KamLAND Collaboration motoki@NDM03

  2. NeutrinoOscillation SuperK day night, SuperK energy spectrum  LMA+LOW LMA SNO NC; ne+nm+nt SMA Flavor transition day/night • LMA LOW KamLAND; Artificial neutrino sources Low energy Long baseline VAC motoki@NDM03

  3. KamLAND KamiokaLiquid scintillator Anti Neutrino Detector • Reactor Anti Neutrino Source. • Energy distortion, LMA • 7Be neutrinos. • Geo neutrinos. motoki@NDM03

  4. The KamLAND Collaboration K.Eguchi, S.Enomoto, K.Furuno, J.Goldman, H.Hanada, H.Ikeda, K.Ikeda, K.Inoue, K.Ishihara, W.Itoh, T.Iwamoto, T.Kwaguchi, T.Kawashima, H.Kinoshita, Y.Kishimoto, M.Koga, Y.Koseki, T.Maeda, T.Mitsui, M.Motoki, K.Nakajima, M.Nakajima, T.Nakajima, H.Ogawa, K.Owada, T.Sakabe, I.Shimizu, J.Shirai, F.Suekane, A.Suzuki, K.Tada, O.Tajima, T.Takayama, K.Tamae, H.Watanabe Tohoku University J.Busenitz, Z.Djurcic, K.McKinny, D.-M.Mei, A.Piepke, E.Yakushev, University of Alabama B.E.Berger, Y.D.Chan, M.P.Decowski, D.A.Dwyer, S.J.Freedman, Y.Fu, B.K.Fujikawa, K.M.Heeger, K.T.Lesko, K.-B.Luk, H.Murayama, D.R.Nygren, C.E.Okada, A.W.P.Poon, H.M.Steiner, L.A.Winslow LBNL/UCBerkeley G.A.Horton-Smith, R.D.McKeown, J.Ritter, B.Tipton, P.Vogel California Institute of Technology C.E.Lane, T.Miletic Drexel University P.W.Gorham, G.Guillian, J.G.Learned, J.Maricic, S.Matsuno, S.Pakvasa University of Hawaii S.Dazeley, S.Hatakeyama, M.Murakami, R.C.Svoboda Louisiana State University B.D.Dieterle, M.DiMauro University of New Mexico J.Detwieler, G.Gratta, K.Ishii, N.Tolich, Y.Uchida Stanford University M.Batygov, W.Bugg, H.Cohn, Y.Efremenko, Y.Kamyshkov, A.Kozlov, Y.Nakamura University of Tennessee L.De Braeckeleer, C.R.Gould, H.J.Karwowski, D.M.Markoff, J.A.Messimore, K.Nakamura, R.M.Rohm, W.Tornow, A.R.Young TUNL Y.-F.Wang IHEP,Beijing motoki@NDM03

  5. a few /day in KamLAND • 54 Japanese Reactors • Average distance 180km • (79 % in 138-214km) • < Eν> ~ 4MeV • ⊿m2~E/L ~10-5 eV2 • Suitable to test LMA solution motoki@NDM03

  6. Reactor neutrino flux at KamLAND • Thermal power, Burn-up, : available for All 54 Japanese Reactors • Reactor type, Volume ratio of new fuel, Enrichment of new fuel, initial mean burn up • Simple model of reactor core. • fission rate • energy spectrum @KamLAND Uncertainty : 2.5% for anti νe motoki@NDM03

  7. motoki@NDM03

  8. Reactor Neutrino detection in Liquid Scintillator motoki@NDM03

  9. Vertex reconstruction Using PMT timing information Source Calibration Data: Z-axis Typically 25cm resolution Position reconstruction: 5cm motoki@NDM03

  10. VertexFitter Performance: Fiducial Volume motoki@NDM03

  11. Energy resolution Along to Z-axis: radioactive source 68Ge ( + ) : 1.012 MeV 65Zn () : 1.116 MeV 60Co ( + ) : 2.506 MeV AmBe (,n) : 2.20, 4.40, 7.6 MeV time dependence: 0.6% 4πcalibration: captured netron events n+pd+g : 2.2 MeV n+12C13C+g : 4.9MeV position dependence: 1.1% • DE/E ~ 7.5% /√E [MeV] • DEsyst=1.9% at 2.6MeV  2.1% for anti ne motoki@NDM03

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  14. Radio active Background in LS motoki@NDM03

  15. DT = |tprompt – t delayed| t = • (214Po:a) = 237 ms 214Bi – 214Po – 210Pb Signal prompt delayed 238U = (3.5±0.5)x10-18 g/g b+g a motoki@NDM03

  16. Delayed coincidence motoki@NDM03

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  20. Vertex position after delayed coincidence motoki@NDM03

  21. Prompt Delayed motoki@NDM03

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  23. KamLAND result Mar. 4 – Oct. 6, 2002 162 ton•yr (145.1 days) Observed54 events (E>2.6MeV) Background 1 ± 1 events Expected86.8 ± 5.6 events Geo Neutrino: 0 – 110 TW (95 % C.L.) motoki@NDM03

  24. Spectral Distortion? No oscillation, flux suppression 2- oscillation: best-fit Data and best oscillation fit consistent at 93% C.L. Data and scaled no-oscillation shape consistent at 53% C.L Need more reactor neutrino and calibration data motoki@NDM03

  25. KamLAND impacts 95%CL LMA 2 LMA 1 KamLAND All combined motoki@NDM03

  26. KamLAND Prospects • Neutrino Oscillation? Precision measurements • Energy Spectrum distortion? • Current reactor power in Japan ~50%. • A new reactor is coming. • LMA 1 or LMA2 • 7Be • Purification system improvement motoki@NDM03

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  29. LMA I, LMA II Before and After New Reactor “Shika” motoki@NDM03

  30. KamLAND Solar motoki@NDM03

  31. Summary • Last year • KamLAND saw a cleardeficitin reactor neutrinos. • Future • KamLAND purification system will be improved for7BeSolar Neutrino detection. • Stable data taking duringreactor shutdown. • LMA1,LMA2will be decided. motoki@NDM03

  32. Appendix motoki@NDM03

  33. Solar Neutrino at KamLAND First observation of real time 7Be neutrinos motoki@NDM03

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