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

Charge /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

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

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

Energy Spectra of Astrophysical neutrinos thermal sources Non-thermal sources

Neutrinos (homemade) Nuclear Reactors (beta decays of fission products: e ) Accelerators pion production and subsequent decay in flight: 

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 ?

Survival probability: L in L osz Neutrino Oscillations

L ≈ 20 km L ≈ km atmospheric neutrinos: E v ~ GeV Oscillations and Atmospheric Neutrinos Pion production and subsequent decays (incl. muon)

Atmospheric Neutrinos and SuperKamiokande Charged current reactions  + N   + N` and e + N  e + N` 50 kt Water Cherenkov Detector

νμνμ νeνe Electron events Muon events Up goingUp going Neutrinos  e No-oscillation Oscillation

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

Oscillations and Solar Neutrinos Neutrino Energy in MeV

The Solar Neutrino Problem Solar Model 0,5

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

SNO Result Flavour transition discovered: 7 sigma ! Reasonable agreement with solar model Neutrinos from the Sun ( e ) transform into   or   

Solar Neutrino Oscillation Determination of  12 ~ 34 0 e  e   m 2 ~ 8 x eV 2 Confirmation by reactor experiment KamLAND

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

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

KamLAND: Energy spectrum

θ sol θ 13, δ θ atm Parametrization Neutrino mixing Flavor Eigenstates Mass Eigenstates 2 mixing angles are measured:            CP violating phase  New experiments

 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

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

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 ~ /d (near) photomultipliers Inner veto

Sensitivity of Double Chooz Exclusion limit 90% cl for dm 2 = eV 2 and a final systematic uncertainty of 0.6%

732 km LNGS Neutrino beam from CERN to Gran Sasso

Precision Tracker (PT) Universität Hamburg: Detector 8.3kg Aktives Target: Blei- Emulsions-Ziegel = ca Tonnen Universit ät Münster

full mixing, 5 years 4.5 x10 19 pot / yearsignal (  m 2 = 1.9 x eV 2 ) signal (  m 2 = 2.4 x eV 2 ) signal (  m 2 = 3.0x 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

BOREXINO sees neutrinos from CERN (August 2006) !

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

First neutrino events in BOREXINO

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

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 ( kt) (≥ 2015) –T2K – phase II: 4 MW + HyperK ( kt) (≥ 2015) USA: NOvA: Fermilab NuMI beam (0.4 MW) + off-axis detector (surface!, 50kt) (ab 2009)

Sensitivity of future experiments on θ 13 90% CL from Huber, Lindner, Rolinec, Schwetz, Winter hep-ph/ ← reactor ← super beam

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

Mainz Data (1998,1999,2001) Direct Mass Experiments: Tritium β-Decay E 0 = 18.6 keV

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)

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/ , Phys. Rev. C59 (1999) 2108

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

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

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:

Neutrinos as Probes …from the Earth and from Astrophysical Objects

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)

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

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

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

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

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

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

Extremely Large Observatories Km 3 Cherenkov detector in the mediterranian sea Km 3 Cherenkov detector at the South Pole (Ice Cube)

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  = combined Diffusive sources Limits from Amanda Ice-Cube ~

Conclusions New results recently Neutrino masses and mixing established Physics beyond the standard model New window to astrophysical observations