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Neutrino Physics L. Oberauer, TU München Graduiertenkolleg Bad Honnef, August 2006
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Content Neutrino sources Intrinsic properties oscillations masses and mixing parameter Neutrinos as probes from the Earth from astrophysical sources
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Charge 0 -1 +2/3 -1/3 Why are neutrinos intresting ? Neutrinos undergo only weak interactions Neutrinos are neutral – intrinsic properties Neutrinos as probes – astrophysical applications Interactions w w,e w,e,s
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Natural Neutrino Sources (experimentally verified) Sun (since 1970) Earth (since 2005) Supernovae (1987) Atmosphere (since ~1990)
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Natural Neutrino Sources (not yet verified) Big Bang Active galactic nuclei Supernovae remnants ?, Gamma ray bursts ?, Supernovae relic neutrinos ?...
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Energy Spectra of Astrophysical neutrinos thermal sources Non-thermal sources
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Neutrinos (homemade) Nuclear Reactors (beta decays of fission products: e ) Accelerators pion production and subsequent decay in flight:
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Intrinsic Neutrino Properties Neutrino masses ? Neutrino mixing ? Dirac or Majorana particle ? CP violation ? Neutrino magnetic moment ? Neutrino oscillations observed, Missing mixing angle 13 Absolute masses and hierarchy ?
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Survival probability: 0 1 2 3 L in L osz Neutrino Oscillations
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L ≈ 20 km L ≈ 13000 km atmospheric neutrinos: E v ~ GeV Oscillations and Atmospheric Neutrinos Pion production and subsequent decays (incl. muon)
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Atmospheric Neutrinos and SuperKamiokande Charged current reactions + N + N` and e + N e + N` 50 kt Water Cherenkov Detector
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νμνμ νeνe Electron events Muon events Up goingUp going Neutrinos e No-oscillation Oscillation
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Result atmospheric Neutrino-Oscillations Best fit: m 2 atm = 2.5×10 -3 eV 2 sin 2 2θ atm = 1.0 Best fit: m 2 atm = 2.5×10 -3 eV 2 sin 2 2θ atm = 1.0 Confirmed by MACRO (Gran Sasso) Soudan (USA) K2K accelerator long baseline (250 km) experiment MINOS (USA) acc. exp. in 2006
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Oscillations and Solar Neutrinos Neutrino Energy in MeV
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The Solar Neutrino Problem Solar Model 0,5
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Sudbury Neutrino Observatory SNO charged current interaction (cc) e + D p + p + e neutral current interaction (nc) x + D x + p + n elastic Neutrino-Electron scattering (cc + nc) x + e x + e 1kt Cherenkov Detector with heavy water
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SNO Result Flavour transition discovered: 7 sigma ! Reasonable agreement with solar model Neutrinos from the Sun ( e ) transform into or
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Solar Neutrino Oscillation Determination of 12 ~ 34 0 e e m 2 ~ 8 x 10 -5 eV 2 Confirmation by reactor experiment KamLAND
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The solar matter effect – evidence by GALLEX/GNO GALLEX/GNO SNO Evidence for matter effect inside the Sun m 2 > m 1 Why are neutrino masses so small? GUT Leptogenesis Survival probability electron neutrino pp- 7Be 8B
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Phys. Rev. Lett. 90 (2003) 021802 Evidence for Oscillation ILL 1979 Gösgen (1986) Chooz (1998) Reactor Experiments Bugey (1994)
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KamLAND: Energy spectrum
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θ sol θ 13, δ θ atm Parametrization Neutrino mixing Flavor Eigenstates Mass Eigenstates 2 mixing angles are measured: CP violating phase New experiments
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13 from reactors? P( e e ) = 1 – cos 4 13 sin 2 2 12 sin 2 ( m 2 sol L/4E) – sin 2 2 13 sin2 ( m 2 atm L/4E) no CP terms no matter effects P L/E(km/MeV) solar atmospheric
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Letter of Intent: Double- Chooz d~1.05 km P~8.4 GW 300mwe far detector no excavation for far detector Far Detector (~300mwe shielding) Near Detector for reactor monitoring
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Double-CHOOZ (far) Detector Puit existant Gamma catcher: scintillator with no Gd 7 m BUFFER Mineral Oil 7 m Shielding steel and external vessel Target- Gd loaded scintillator: ~ 85 /d (far) and ~ 4 10 3 /d (near) photomultipliers Inner veto
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Sensitivity of Double Chooz Exclusion limit 90% cl for dm 2 = 2.8 10 -3 eV 2 and a final systematic uncertainty of 0.6%
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732 km LNGS Neutrino beam from CERN to Gran Sasso
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Precision Tracker (PT) Universität Hamburg: Detector 8.3kg Aktives Target: 200.000 Blei- Emulsions-Ziegel = ca. 1.800 Tonnen Universit ät Münster
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full mixing, 5 years run @ 4.5 x10 19 pot / yearsignal ( m 2 = 1.9 x 10 -3 eV 2 ) signal ( m 2 = 2.4 x 10 -3 eV 2 ) signal ( m 2 = 3.0x 10 -3 eV 2 ) BKGDOPERA 1.8 kton fid. 6.6(10) 10.5(15.8) 16.4(24.6) 0.7(1.1) + brick finding + 3 prong decay 8.0(12.1) 12.8(19.2) 19.9(29.9) 1.0(1.5) Background reduction 8.0(12.1) 12.8(19.2) 19.9(29.9) 0.8(1.2) (…) with CNGS beam upgrade (X 1.5) → sensitivity → sensitivity
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BOREXINO sees neutrinos from CERN (August 2006) !
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Cosmic muons (background) Time of flight (CERN to LNGS) ~ 2.4 ms Data analysis of 30 h measurement and 55 t water as target
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First neutrino events in BOREXINO
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Θ 13 with accelerator physics with (anti-v) Neutrino appearance: θ 13, δ CP, Mass hierarchy but degeneracy & correlation effects! Present limit from CHOOZ: sin 2 (2 13 ) < 0.2
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Neutrino Superbeam Projects Japan: –T2K – phase I: 0.75MW (JPARC) + SuperK (22.5kt) (ab 2009) sin 2 2 13 >0.006 (90%) (5 Jahre) –T2K – phase II: 4 MW + HyperK (500-1000 kt) (≥ 2015) –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)
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Sensitivity of future experiments on θ 13 90% CL from Huber, Lindner, Rolinec, Schwetz, Winter hep-ph/0403068 ← reactor ← super beam
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Absolute Neutrino Mass Measurements Kinematic tests (tritium decay) Search for the neutrinoless double- beta decay
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Mainz Data (1998,1999,2001) Direct Mass Experiments: Tritium β-Decay E 0 = 18.6 keV
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KATRIN ~70 m beamline, 40 s.c. solenoids The KArlsruhe TRItium Neutrino Experiment The KArlsruhe TRItium Neutrino Experiment Commissioning in 2008 m v < 0.2eV (90%CL)
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Neutrinoless Double-Beta- Decay 0 :(A,Z) (A,Z+2) + 2e - d d u u e-e- e-e- W-W- W-W- e e L=2 Majorana nature, Mass scale, Majorana CP phases m ee = | i U ei ² m i | Effective neutrino mass: Heidelberg-Moskau Collaboration, Eur.Phys.J. A12 (2001) 147 IGEX Collaboration, hep-ex/0202026, Phys. Rev. C59 (1999) 2108
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H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004 Peak at 2039 keV in the Heidelberg-Moscow experiment ! Effect or background ?? Evidence for neutrinoless Double-beta Decay ? Wanted: New experiments ! GERDA ( 76 Ge) Cuoricino ( 130 Te in cryogenic detectors) NEMO (different isotopes in large drift-chambers) COBRA ( 116 Cd) SNO+ ( 150 Nd) …and many more projects
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Phase I: 20kg enriched (86%) 76 Ge, vgl. HDM Phase II: 35-40kg Phase III: ~500kg GERmanium Detector Array Method: HP Ge-diodes (enriched in 76 Ge) in cryogenic fluid shield (optional active). Q ββ = 2039 keV HP Ge-diodes (enriched in 76 Ge) in cryogenic fluid shield (optional active). Q ββ = 2039 keV
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GERDA Sensitivity & Neutrino Mass | m ee | in eV Lightest neutrino (m 1 ) in eV F.Feruglio, A. Strumia, F. Vissani, NPB 659 H.V. Klapdor-Kleingrothaus, A. Dietz, O. Chkvorets, I.V. Krivosheina, NIM A, 2004 Phase I: Phase II: Phase III:
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Neutrinos as Probes …from the Earth and from Astrophysical Objects
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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)
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First detection in KamLAND Nature, 28. July 2005 Geo-neutrino energy spectrum reactors background Excess due to Geo-neutrinos
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Future Neutrino Observatories Unsegmented 50 kt liquid scintillator LENA HyperKamiokande (1 Mt Water Cherenkov) …Liquid Argon ~100 kt TPC
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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
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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
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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
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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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Extremely Large Observatories Km 3 Cherenkov detector in the mediterranian sea Km 3 Cherenkov detector at the South Pole (Ice Cube)
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Amanda Frejus E ν E -3.8 A change in the slope would indicate a non-atmospheric component Atmospheric neutrino Waxmann-Bahcall limit: Model-independent upper bound = 2 = 00-03 combined Diffusive sources Limits from Amanda Ice-Cube ~ 3 10 -9
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Conclusions New results recently Neutrino masses and mixing established Physics beyond the standard model New window to astrophysical observations
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