1. New Results from KamLAND and Prospects for Observation of Terrestrial Neutrinos Nikolai Tolich

2. July 9, 2004LBL Journal Club Meeting2 KamLAND Collaboration T. Araki 1, K. Eguchi 1, S. Enomoto 1, K. Furuno 1, K. Ichimura 1, H. Ikeda 1, K. Inoue 1, K. Ishihara 1, T. Iwamoto 1, T. Kawashima 1, Y. Kishimoto 1, M. Koga 1, Y. Koseki 1, T. Maeda 1, T. Mitsui 1, M. Motoki 1, K. Nakajima 1, H. Ogawa 1, K. Owada 1, J.-S. Ricol 1, I. Shimizu 1, J. Shirai 1, F. Suekane 1, A. Suzuki 1, K. Tada 1, O. Tajima 1, K. Tamae 1, Y. Tsuda 1, H. Watanabe 1, J. Busenitz 2, T. Classen 2, Z. Djurcic 2, G. Keefer 2, K. McKinny 2, D-M. Mei 2, A. Piepke 2, E. Yakushev 2, B.E. Berger 3, Y.D. Chan 3, M.P. Decowski 3, D.A. Dwyer 3, S.J. Freedman 3, Y. Fu 3, B.K. Fujikawa 3, J. Goldman 3, F. Gray 3, K.M. Heeger 3, K.T. Lesko 3, K.-B. Luk 3, H. Murayama 3, A.W.P. Poon 3, H.M. Steiner 3, L.A. Winslow 3, G.A. Horton-Smith 4, C. Mauger 4, R.D. McKeown 4, P. Vogel 4, C.E. Lane 5, T. Miletic 5, P.W. Gorham 6, G. Guillian 6, J.G. Learned 6, J. Maricic 6, S. Matsuno 6, S. Pakvasa 6, S. Dazeley 7, S. Hatakeyama 7, A.Rojas 7, R. Svoboda 7, B.D. Dieterle 8, J. Detwiler 9, G. Gratta 9, K. Ishii 9, N. Tolich 9, Y. Uchida 9, M. Batygov 10, W. Bugg 10, Y. Efremenko 10, Y. Kamyshkov 10, A. Kozlov 10, Y. Nakamura 10, H.J. Karwowski 11, D.M. Markoff 11, J.A. Messimore 11, K. Nakamura 11, R.M. Rohm 11, W. Tornow 11, R. Wendell 11, A.R. Young 11, M.-J. Chen 12, Y.-F. Wang 12, and F. Piquemal 13 1 Research Center for Neutrino Science, Tohoku University, Sendai 980-8578, Japan 2 Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA 3 Physics Department, University of California at Berkeley and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 4 W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA 5 Physics Department, Drexel University, Philadelphia, Pennsylvania 19104, USA 6 Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA 7 Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA 8 Physics Department, University of New Mexico, Albuquerque, New Mexico 87131, USA 9 Physics Department, Stanford University, Stanford, California 94305, USA 10 Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA 11 Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA and Physics Departments at Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill 12 Institute of High Energy Physics, Beijing 100039, People's Republic of China 13 CEN Bordeaux-Gradignan, IN2P3-CNRS and University Boreaux I, F-33175 Gradignan Cedex, France

3. July 9, 2004LBL Journal Club Meeting3 An Attractive Group

4. July 9, 2004LBL Journal Club Meeting4 Detecting Anti-neutrinos at KamLAND KamLAND (Kamioka Liquid scintillator Anti- Neutrino Detector) d p e+e+ 0.5 MeV  2.2 MeV  n p 0.5 MeV  e e-e- Inverse beta decay e + p → e + + n The positron losses its energy then annihilates with an electron The neutron first thermalizes then captures on a proton with a mean capture time of ~200  s Prompt Delayed

5. July 9, 2004LBL Journal Club Meeting5 Detector Electronics Hut Steel Sphere Water Cherenkov outer detector 225 PMTs 1 kton liquid- scintillator PMTs 1325 17” 554 20” 34% coverage 1km Overburden

6. July 9, 2004LBL Journal Club Meeting6 Inside the Detector

7. July 9, 2004LBL Journal Club Meeting7 KamLAND Situated to Detect Reactor Anti-neutrinos Kashiwazaki Takahama Ohi KamLAND

8. July 9, 2004LBL Journal Club Meeting8 History Repeating Fred Reines preparing a neutrino detector (circa 1953)

9. July 9, 2004LBL Journal Club Meeting9 So were Fred Reines background from Terrestrial Anti-neutrinos?

10. July 9, 2004LBL Journal Club Meeting10 Total Heat from the Earth Conductive heat flow measured from bore-hole temperature gradient and conductivity Total heat flow 44TW In 1862 Lord Kelvin used the temperature gradient to estimate the age of the Earth to be 20-400 million years old

11. July 9, 2004LBL Journal Club Meeting11 Radiogenic Heat 238 U generates 8.0TW of radiongenic heat in the Earth 232 Th generates 8.3TW of radiongenic heat in the Earth Beta decays produce electron anti-neutrinos

12. July 9, 2004LBL Journal Club Meeting12 Terrestrial Anti-neutrino signal 238 U decay chain 232 Th decay chain KamLAND is only sensitive to anti-neutrinos above 1800keV

13. July 9, 2004LBL Journal Club Meeting13 Terrestrial Anti-neutrino signal at KamLAND Reactor Background U+Th U

14. July 9, 2004LBL Journal Club Meeting14 Structure of the Earth Image by Colin Rose Structure of the Earth determined from Seismic data

15. July 9, 2004LBL Journal Club Meeting15 Convection in the Earth The mantle convects even though it is solid Oceanic crust is being renewed at mid-ocean ridges and recycled at subduction zones

16. July 9, 2004LBL Journal Club Meeting16 U and Th in the Earth U and Th are thought to be absent from the core and present in the Silicate Earth at ~2.75 times CI carbonaceous chondrites concentrations The U concentration in the silicate Earth is 20ppm The Th concentration in the silicate Earth is 80ppm The Th/U ratio is ~4

17. July 9, 2004LBL Journal Club Meeting17 The Expected Terrestrial Anti-neutrino Flux The activity per unit mass The number of neutrinos per decay chain per unit energy The mass concentration as a function of position in the Earth The density as a function of position in the Earth The neutrino survival probability as a function of distance from KamLAND Given a model of the Earth the anti-neutrino flux per unit energy at KamLAND can be calculated

18. July 9, 2004LBL Journal Club Meeting18 Reference Earth Model Earth split into eight sections: Upper Continental Crust (UCC), Middle Continental Crust (MCC), Lower Continental Crust (LCC), Oceanic Crust (OC), Upper Mantle (UM), Lower Mantle (LM), Continental Sediment (CS), Oceanic Sediment (OS)

19. July 9, 2004LBL Journal Club Meeting19 Cumulative Terrestrial Anti-neutrino Flux Expected at KamLAND

20. July 9, 2004LBL Journal Club Meeting20 Terrestrial Anti-neutrino map of the Earth

21. July 9, 2004LBL Journal Club Meeting21 Measurement at KamLAND Total Measured Total Heat Flow

22. New Reactor Results* *T. Araki et al. arXiv:hep-ex/0406035 June 13, 2004 submitted to Phys. Rev. Lett.

23. July 9, 2004LBL Journal Club Meeting23 Introduction to reactor measurement Nuclear Reactor KamLAND L e

24. July 9, 2004LBL Journal Club Meeting24 Determining the Event Vertex (2.5MeV) (1.1MeV) (1.0MeV)

25. July 9, 2004LBL Journal Club Meeting25 Tagged Cosmogenics used as Calibration Device 12 B 12 N τ=29.1ms Q=13.4MeV τ=15.9ms Q=17.3MeV μ

26. July 9, 2004LBL Journal Club Meeting26 Energy Calibration Using  Sources and 12 B/ 12 N 68 Ge 65 Zn 60 Co n-p n- 12 C

27. July 9, 2004LBL Journal Club Meeting27 Selecting Electron Anti-neutrinos R prompt, R delayed < 5.5m ΔR < 2m 0.5μs < ΔT < 1ms 1.8MeV < E delayed < 2.6MeV 2.6MeV < E prompt < 8.5MeV 89.8% tagging efficiency 33% increase in volume e+e+ 0.5 MeV  2.2 MeV  0.5 MeV  Prompt Delayed

28. July 9, 2004LBL Journal Club Meeting28 Japan Nuclear Reactor Scandal

29. July 9, 2004LBL Journal Club Meeting29 2003 saw a substantial dip in reactor anti-neutrino flux

30. July 9, 2004LBL Journal Club Meeting30 Good correlation with reactor flux Fit constrained through known background  2 /dof=2.1/4 90% CL No oscillation expected

31. July 9, 2004LBL Journal Club Meeting31 Energy spectrum shows distortion Best fit  2 /dof=18.3/18 (goodness of fit is 42%) Fit to rescaled reactor spectrum  2 /dof=43.4/19 (excluded at 99.89% CL)

32. July 9, 2004LBL Journal Club Meeting32 Oscillations with L/E KamLAND sees reactor neutrinos from different distances Hypothetical oscillation curve for single reactor distance

33. July 9, 2004LBL Journal Club Meeting33 Alternative neutrino propagation models Decay * excluded at 95% CL Decoherence † excluded at 94% CL * V.Barger et al. Phys. Rev. Lett., 82 (1999) 2640 † E.Lisi et al. Phys. Rev. Lett., 85 (2000) 1166

34. July 9, 2004LBL Journal Club Meeting34 Two flavor rate and shape analysis Best fit  m 2 =8.3×10 -5 eV 2 sin 2 2  =0.83 LMA0 excluded at 94% CL LMA2 excluded at 99.6% CL Previous ResultNew Result

35. July 9, 2004LBL Journal Club Meeting35 Combined solar and KamLAND two flavor result