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Neutrino Physics

Neutrino Physics. L. Oberauer, TU München Graduiertenkolleg Bad Honnef, August 2006. Content. Neutrino sources Intrinsic properties oscillations masses and mixing parameter Neutrinos as probes from the Earth from astrophysical sources. Why are neutrinos intresting ?.

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Neutrino Physics

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  1. Neutrino Physics L. Oberauer, TU München Graduiertenkolleg Bad Honnef, August 2006

  2. Content • Neutrino sources • Intrinsic properties oscillations masses and mixing parameter • Neutrinos as probes from the Earth from astrophysical sources

  3. Why are neutrinos intresting ? Interactions w w,e w,e,s Charge 0 -1 +2/3 -1/3 • Neutrinos undergo only weak interactions • Neutrinos are neutral – intrinsic properties • Neutrinos as probes – astrophysical applications

  4. Natural Neutrino Sources (experimentally verified) Atmosphere (since ~1990) Sun (since 1970) Earth (since 2005) Supernovae (1987)

  5. Natural Neutrino Sources (not yet verified) Big Bang Active galactic nuclei Supernovae remnants ?, Gamma ray bursts ?, Supernovae relic neutrinos ?...

  6. Energy Spectra of Astrophysical neutrinos thermal sources Non-thermalsources

  7. Neutrinos (homemade) Nuclear Reactors (beta decays of fission products: ne) Accelerators pion production and subsequent decay in flight: nm

  8. Intrinsic Neutrino Properties • Neutrino masses ? • Neutrino mixing ? • Dirac or Majorana particle ? • CP violation ? • Neutrino magnetic moment ? Neutrino oscillations observed, Missing mixing angle Q13 Absolute masses and hierarchy ?

  9. Survival probability: 0 3 2 1 L in Losz Neutrino Oscillations

  10. L ≈ 20 km atmosphericneutrinos:Ev ~ GeV L ≈ 13000 km Oscillations and Atmospheric Neutrinos Pion production and subsequent decays (incl. muon)

  11. Atmospheric Neutrinos and SuperKamiokande 50 kt Water Cherenkov Detector Charged current reactions nm + N ->m + N` and ne + N -> e + N`

  12. Muon events Electron events νμ νe m e No-oscillation Oscillation Up going Up going Neutrinos

  13. Result atmospheric Neutrino-Oscillations • Confirmed by • MACRO (Gran Sasso) • Soudan (USA) • K2K accelerator long baseline (250 km) experiment • MINOS (USA) acc. exp. in 2006 Best fit:m2atm = 2.5×10-3 eV2 sin22θatm = 1.0

  14. Neutrino Energy in MeV Oscillations and Solar Neutrinos

  15. The Solar Neutrino Problem Solar Model 0,5

  16. Sudbury Neutrino Observatory SNO • charged current interaction (cc) ne+ D -> p + p + e • neutral current interaction (nc) nx + D ->nx + p + n • elastic Neutrino-Electron scattering (cc + nc) nx+ e ->nx + e 1kt Cherenkov Detector with heavywater

  17. SNO Result • Flavour transition discovered: 7 sigma ! • Reasonable agreement with solar model Neutrinos from the Sun (ne) transform into nmor nt !

  18. Solar Neutrino Oscillation • Determination of Q12 ~ 340 • ne nm,t • Dm2 ~ 8 x 10-5 eV2 • Confirmation by reactor experiment KamLAND

  19. The solar matter effect – evidence by GALLEX/GNO • Evidence for matter effect inside the Sun • m2 > m1 • Why are neutrino masses so small? • GUT • Leptogenesis Survival probability electron neutrino SNO 8B GALLEX/GNO pp- 7Be

  20. Phys. Rev. Lett. 90 (2003) 021802 Reactor Experiments ILL 1979 Gösgen (1986) Chooz (1998) Bugey (1994) Evidence for n Oscillation

  21. KamLAND: Energy spectrum

  22. Parametrization Neutrino mixing Flavor Eigenstates Mass Eigenstates θsol θ13, δ θatm 2 mixing angles are measured: Q12 ~ 340 Q23 ~ 450 Q13 ? CP violating phase d ? New experiments

  23. Q13 from reactors? P(nene) = 1 – cos4q13 sin2 2q12 sin2(Dm2sol L/4E) – sin2 2q13 sin2 (Dm2atm L/4E) no CP terms no matter effects solar P atmospheric L/E(km/MeV)

  24. Letter of Intent: Double-Chooz Near Detector for reactor monitoring • d~1.05 km • P~8.4 GW • 300mwe far detector • no excavation for far detector Far Detector (~300mwe shielding)

  25. Double-CHOOZ(far) Detector Shielding steel and external vessel 7 m Target- Gd loaded scintillator: ~ 85 /d (far) and ~ 4 103/d (near) Gamma catcher: scintillator with no Gd 7 m BUFFER Mineral Oil 7 m Inner veto photomultipliers Puit existant

  26. Sensitivity of Double Chooz Exclusion limit 90% cl for dm2 = 2.8 10-3 eV2 and a final systematic uncertainty of 0.6%

  27. Neutrino beam from CERN to Gran Sasso 732 km LNGS

  28. Detector Precision Tracker (PT)Universität Hamburg: Aktives Target:200.000 Blei-Emulsions-Ziegel= ca. 1.800 Tonnen Universität Münster 8.3kg

  29. nm→nt sensitivity full mixing, 5 years run @ 4.5 x1019 pot / year (…) with CNGS beam upgrade (X 1.5)

  30. BOREXINO sees neutrinos from CERN (August 2006) !

  31. Data analysis of 30 h measurement and 55 t water as target Time of flight (CERN to LNGS) ~ 2.4 ms Cosmic muons (background)

  32. First neutrino events in BOREXINO

  33. (anti-v) with Θ13 with accelerator physics Present limit from CHOOZ: sin2(213) < 0.2 Neutrino appearance: θ13 , δCP, Mass hierarchy abut degeneracy & correlation effects!

  34. Neutrino Superbeam Projects • Japan: • T2K – phase I: 0.75MW (JPARC) + SuperK (22.5kt) (ab 2009)sin22q13>0.006 (90%) (5 Jahre) • T2K – phase II: 4 MW + HyperK (500-1000 kt) (≥ 2015) • USA:NOvA: Fermilab NuMI beam (0.4 MW) +off-axis detector (surface!, 50kt) (ab 2009)

  35. Sensitivity of future experiments onθ13 ← reactor ← super beam 90% CL from Huber, Lindner, Rolinec, Schwetz, Winter hep-ph/0403068

  36. Absolute Neutrino Mass Measurements Kinematic tests (tritium decay) Search for the neutrinoless double-beta decay

  37. Mainz Data (1998,1999,2001) Direct Mass Experiments: Tritium β-Decay E0 = 18.6 keV

  38. TheKArlsruhe TRItium Neutrino Experiment Commissioning in 2008mv < 0.2eV (90%CL) KATRIN ~70 m beamline, 40 s.c. solenoids

  39. u e- d ne L=2 W- ne W- d e- u Heidelberg-Moskau Collaboration, Eur.Phys.J. A12 (2001) 147 IGEX Collaboration, hep-ex/0202026, Phys. Rev. C59 (1999) 2108 Neutrinoless Double-Beta-Decay 0: (A,Z)  (A,Z+2) + 2e- mee = |iUei ²mi | Effective neutrino mass: • Majorana nature, Mass scale, Majorana CP phases

  40. H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004 Evidence for neutrinoless Double-beta Decay ? • Wanted: New experiments ! • GERDA ( 76Ge) • Cuoricino (130Te in cryogenic detectors) • NEMO (different isotopes in large drift-chambers) • COBRA (116Cd) • SNO+ (150Nd) • …and many more projects Peak at 2039 keV in the Heidelberg-Moscow experiment ! Effect or background ??

  41. GERmanium Detector Array Method: HP Ge-diodes (enriched in 76Ge) in cryogenic fluid shield(optional active) . Qββ= 2039 keV Phase I: 20kg enriched (86%) 76Ge, vgl. HDMPhase II: 35-40kgPhase III: ~500kg

  42. H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004 | mee| in eV Phase I: Lightest neutrino (m1) in eV Phase II: Phase III: GERDA Sensitivity & Neutrino Mass F.Feruglio, A. Strumia, F. Vissani, NPB 659

  43. Neutrinos as Probes …from the Earth and from Astrophysical Objects

  44. Geo-Neutrinos • Direct neutrino observation: • what is the contribution of radioactivity to the Earth‘s heat flow (~ 40 TW) ? • direct test of the Bulk Silicate Earth model • what is the energy source of the Earth magnetic field ? • test of unorthodox models (i.e. breeder reactor in the core)

  45. First detection in KamLAND reactors reactors Geo-neutrino energy spectrum background Excess due to Geo-neutrinos Nature, 28. July 2005

  46. Future Neutrino Observatories Unsegmented 50 kt liquid scintillator LENA …Liquid Argon ~100 kt TPC HyperKamiokande (1 Mt Water Cherenkov)

  47. LAGUNA • Large Aparatus for Grand Unification and Neutrino Astronomy • European initiative (France, Germany, Italy, Switzerland, UK, Poland, Finland) • Aim: Design studies for all 3 kinds of detevtors (water Ch, scintillator, liquid argon) until ~ 2010

  48. Physics goals of future Neutrino Observatories • Gravitational collapse • Star formation rate in the early universe • Thermonuclear fusion reactions • Baryon number violation (Proton decay) • Leptonic CP – violation • Geophysics • Indirect search for Dark Matter • Active Galactic Nuclei – UHE Neutrinos

  49. One example for LENA: Detection of the Diffuse Supernova Neutrino Background (DSNB) ? • up to now only limits • flux and spectral shape depend on • Star formation rate • Gravitational collapse model

  50. Star formation rate Star formation: Large uncertainties Optical and infrared observations LENA: 70 until 120 events in 10 years 1 < z < 2: around 25% Pulse shape analysis: distinction between models of supernova mechanism

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