1 / 35

Solar neutrino results, KamLAND & prospects

Solar neutrino results, KamLAND & prospects. Solar Neutrino History KamLAND Prospects. www.awa.tohoku.ac.jp/~kengo/NuFact03.pdf. Kengo Nakamura Duke/TUNL. Solar Neutrino Problem. Neutrino Oscillation. http://hitoshi.berkeley.edu/neutrino. Cl, Kamiokande,Ga  LMA,SMA,LOW,VAC

snowy
Download Presentation

Solar neutrino results, KamLAND & prospects

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Solar neutrino results, KamLAND & prospects • Solar Neutrino History • KamLAND • Prospects www.awa.tohoku.ac.jp/~kengo/NuFact03.pdf Kengo Nakamura Duke/TUNL Kengo Nakamura

  2. Solar Neutrino Problem Kengo Nakamura

  3. Neutrino Oscillation http://hitoshi.berkeley.edu/neutrino • Cl, Kamiokande,Ga  LMA,SMA,LOW,VAC • SuperK day night, SuperK energy spectrum  LMA+LOW LMA SMA SNO NC; ne+nm+nt LOW • Flavor transition • SNO day/night • LMA VAC 95%CL KamLAND; Man made neutrino sources Kengo Nakamura

  4. SNO result PRL89(2002)011301 Without the constraint on energy (SSM) • First direct measurement of active 8B n. • Strong evidence for neutrino flavor transition. • Total 8B n agrees with SSM. • SNO Day/night + All solar  LMA. Kengo Nakamura

  5. SNO Status • Neutron capture on Cl • Large s of neutron capture on Cl • 8.6MeV multiple gs • Good light isotropy • Better NC extraction • Result is expected in a few months? A.Poon I.O.P. HEPP Particle Physics 2003, Durham • Installation of Neutral Current Detector Array • n+3Hep+t • Independent NC measurement(syst.+9.1/-8.5+/- 4.5 %) • Sept. 03  ? Kengo Nakamura

  6. KamLAND Kamioka Liquid scintillator Anti Neutrino Detector • Reactor Anti Neutrino Source. • Energy distortion? under Lab. condition. • LMA? • CPT invariance. • 7Be neutrinos. (Evis) Kengo Nakamura

  7. a few /day in KamLAND • Thermal power, Burn-up, Fuel change record data, Simple model of reactor core. • fission rate • energy spectrum @KamLAND • Korea(2.3+- 0.2% @N(n) ) Kengo Nakamura

  8. KamLAND Detector 2700m.w.e. Evis=En-0.78 MeV 20m 20m Kengo Nakamura

  9. 68Ge ( + ) : 1.012 MeV 65Zn () : 1.116 MeV 60Co ( + ) : 2.506 MeV AmBe (,n) : 2.20, 4.40, 7.6 MeV n+pd+g : 2.2 MeV n+12C13C+g: 4.9MeV Energy resolution • DE/E ~ 7.5% /√E [MeV] • DEsyst=1.9% at 2.6MeV  2.1% for anti ne n spallation m Kengo Nakamura

  10. AmBe Neutrons 660msec Capture time = 190msec Delayed coincidence effi = 95.3 % Detection effi= 98.8% Kengo Nakamura

  11. Vertex reconstruction 5cm resolution Uniform 2.2MeV g 4.1% uncertainty on number of neutrinos coming from fiducial mass ratio Kengo Nakamura

  12. 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 Kengo Nakamura

  13. Radioactive Background in LS Kengo Nakamura

  14. Kengo Nakamura

  15. Neutrino Event selection Details • Timing correlation in PMTs • no m veto signals • 0.5 < T < 660 msec • 1.8 < Edelayed< 2.6 MeV • R < 5 m : 409 ton, 3.46x1031 free protons • R < 1.6 m, Rd > 1.2 m • Veto for 2msec. after muons. • Veto for 2sec. after muons (E>106p.e.) (0.02Hz) • Cylindrical (R=3m) 2sec veto around muons (E<106p.e.)  tagging efficiency 78.3% Kengo Nakamura

  16. Vertex position after delayed coincidence Kengo Nakamura

  17. Prompt Delayed (n12C) Kengo Nakamura

  18. 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 Kengo Nakamura

  19. KamLAND impacts 95%CL LMA 2 LMA1 KamLAND All combined Kengo Nakamura

  20. 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 Kengo Nakamura

  21. 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 Kengo Nakamura

  22. c2projection LMA II LMA I Kengo Nakamura

  23. LMA I Before and After Shika LMA II Kengo Nakamura

  24. Solar n @ KamLAND • No direct observation of 7Be n. • Improve KamLAND purification system. • 210Pb; 10-20 g/g  10-25 g/g (Water extraction) • Air tight valve housings. • Testing the water extraction. Kengo Nakamura

  25. Expected Kengo Nakamura

  26. XMASS Kengo Nakamura

  27. Summary • Last year • 8B neutrino measurement and strong evidence of neutrino flavor transition by SNO. • KamLAND observed a clear deficit in reactor neutrinos. • Current Status related to KamLAND and SNO • SNO cl results coming soon and new NC detector installation. • KamLAND stable n data taking during reactor shutdown. • Future • KamLAND update results. • KamLAND purification system will be improved for 7Be Solar neutrino detection. Kengo Nakamura

  28. Backup slides Kengo Nakamura

  29. How to calculate neutrino flux from reactors Kengo Nakamura

  30. Solar Neutrino at KamLAND Kengo Nakamura

  31. Matter effect Kengo Nakamura

  32. q13 The KamLAND is actually measuring; Kengo Nakamura

  33. Trigger efficiency Kengo Nakamura

  34. Kengo Nakamura

  35. c2projection Kengo Nakamura

More Related