1. Recent Results and Prospects from KamLAND
Nikolai Tolich

2. KamLAND Collaboration
T. Araki1, K. Eguchi1, S. Enomoto1, K. Furuno1, K. Ichimura1, H. Ikeda1, K. Inoue1, K. Ishihara1, T. Iwamoto1,
T. Kawashima1, Y. Kishimoto1, M. Koga1, Y. Koseki1, T. Maeda1, T. Mitsui1, M. Motoki1, K. Nakajima1, H. Ogawa1,
K. Owada1, J.-S. Ricol1, I. Shimizu1, J. Shirai1, F. Suekane1, A. Suzuki1, K. Tada1, O. Tajima1, K. Tamae1, Y. Tsuda1,
H. Watanabe1, J. Busenitz2, T. Classen2, Z. Djurcic2, G. Keefer2, K. McKinny2, D-M. Mei2, A. Piepke2, E. Yakushev2,
B.E. Berger3, Y.D. Chan3, M.P. Decowski3, D.A. Dwyer3, S.J. Freedman3, Y. Fu3, B.K. Fujikawa3, J. Goldman3,
F. Gray3, K.M. Heeger3, K.T. Lesko3, K.-B. Luk3, H. Murayama3, A.W.P. Poon3, H.M. Steiner3, L.A. Winslow3,
G.A. Horton-Smith4, C. Mauger4, R.D. McKeown4, P. Vogel4, C.E. Lane5, T. Miletic5, P.W. Gorham6, G. Guillian6,
J.G. Learned6, J. Maricic6, S. Matsuno6, S. Pakvasa6, S. Dazeley7, S. Hatakeyama7, A.Rojas7, R. Svoboda7,
B.D. Dieterle8, J. Detwiler9, G. Gratta9, K. Ishii9, N. Tolich9, Y. Uchida9, M. Batygov10, W. Bugg10, Y. Efremenko10,
Y. Kamyshkov10, A. Kozlov10, Y. Nakamura10, H.J. Karwowski11, D.M. Markoff11, J.A. Messimore11, K. Nakamura11,
R.M. Rohm11, W. Tornow11, R. Wendell11, A.R. Young11, M.-J. Chen12, Y.-F. Wang12, and F. Piquemal13
1Research Center for Neutrino Science, Tohoku University, Sendai , Japan
2Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA
3Physics Department, University of California at Berkeley and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
4W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
5Physics Department, Drexel University, Philadelphia, Pennsylvania 19104, USA
6Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
7Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
8Physics Department, University of New Mexico, Albuquerque, New Mexico 87131, USA
9Physics Department, Stanford University, Stanford, California 94305, USA
10Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
11Triangle 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
12Institute of High Energy Physics, Beijing , People's Republic of China
13CEN Bordeaux-Gradignan, IN2P3-CNRS and University Boreaux I, F Gradignan Cedex, France
August 16, 2004
PASCOS '04

3. Introduction to reactor measurement
KamLAND ne
Nuclear Reactor L
August 16, 2004
PASCOS '04

4. KamLAND Situated to Detect Reactor Anti-neutrinos
Kashiwazaki
KamLAND
Takahama
Ohi
August 16, 2004
PASCOS '04

5. Detecting Anti-neutrinos at KamLAND
Delayed
Prompt
KamLAND (Kamioka Liquid scintillator Anti-Neutrino Detector)
2.2 MeV g
0.5 MeV 
0.5 MeV  e- e+ n p p
Inverse beta decay
ne + p → e+ + n d ne
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 ~200ms
August 16, 2004
PASCOS '04

6. 1 kton liquid-scintillator
1km Overburden
The Detector
Electronics Hut
Steel Sphere
PMTs ”
554 20”
34% coverage
1 kton liquid-scintillator
Water Cherenkov outer detector 225 PMTs
August 16, 2004
PASCOS '04

7. Inside the Detector
August 16, 2004
PASCOS '04

8. Determining the Event Vertex
(2.5MeV)
(1.1MeV)
(1.0MeV)
August 16, 2004
PASCOS '04

9. Tagged Cosmogenics used as Calibration Device
τ=29.1ms
Q=13.4MeV
τ=15.9ms
Q=17.3MeV μ
August 16, 2004
PASCOS '04

10. Fraction of volume used verified using μ-produced 12B/12N and n
Neutrons
12B/12N
August 16, 2004
PASCOS '04

11. Energy Calibration Using g Sources and 12B/12N
n-p
n-12C
68Ge
60Co
65Zn
Includes Birks law, Cherenkov light to obtain constants for γ and e–type depositions
August 16, 2004
PASCOS '04

12. Selecting Electron Anti-neutrinos
Rprompt, Rdelayed < 5.5m
ΔR < 2m
0.5μs < ΔT < 1ms
1.8MeV < Edelayed < 2.6MeV
2.6MeV < Eprompt < 8.5MeV
89.8% tagging efficiency
33% increase in volume
Delayed
Prompt
2.2 MeV g
0.5 MeV 
0.5 MeV  e+
August 16, 2004
PASCOS '04

13. Japan Nuclear Reactor Scandal
August 16, 2004
PASCOS '04

14. 2003 saw a substantial dip in reactor anti-neutrino flux
August 16, 2004
PASCOS '04

15. Good correlation with reactor flux
Fit constrained through known background c2/dof=2.1/4
No oscillation expected
90% CL
August 16, 2004
PASCOS '04

16. Energy spectrum shows distortion
Best fit c2/dof=18.3/18 (goodness of fit is 42%)
Fit to rescaled reactor spectrum c2/dof=43.4/19 (excluded at 99.89% CL)
August 16, 2004
PASCOS '04

17. Oscillations with L/E
KamLAND sees reactor neutrinos from different distances
Hypothetical oscillation curve for single reactor distance
August 16, 2004
PASCOS '04

18. 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
August 16, 2004
PASCOS '04

19. Two flavor rate and shape analysis
LMA2 excluded at 99.6% CL
Best fit
Dm2=8.3×10-5eV2
sin22q=0.83
LMA0 excluded at 94% CL
August 16, 2004
PASCOS '04

20. Improvement since first result
New Result
Previous Result
August 16, 2004
PASCOS '04

21. Combined solar and KamLAND two flavor result
August 16, 2004
PASCOS '04

22. Prospects Measure the global concentration of U and Th in the Earth
Solar anti-neutrinos
Solar neutrinos
Exotic nucleon decay modes
Observe supernova neutrinos
Geo Signal
Reactor Signal
August 16, 2004
PASCOS '04