neutrinos as probes...hql, munich, october 16th-20th, 2006 l. oberauer, tu munich energy spectra of...
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Astrophysical Neutrinos
Neutrinos as probes
HQL, Munich, October 16th-20th, 2006
L. Oberauer, TU Munich
L ≈ 20 km
L ≈ 13000 km
atmosphericneutrinos:Ev ~ GeV
Pion production and subsequent decays (incl. muon)
π −> μ + νμ
μ −> e + νμ + νe
⎟⎟⎠
⎞⎜⎜⎝
⎛ Δ=→
νμ θνν
ELmP atm
atmx
222 27.1sin2sin)(
Oscillations and Atmospheric Neutrinos
Atmospheric Neutrinos and SuperKamiokande
Charged current reactions
νμ + N −> μ + N` and
νe + N −> e + N`
50 kt WaterCherenkovDetector
Result atmospheric Neutrino-Oscillations
Best fit:Δm2
atm = 2.5×10-3 eV2
sin22θatm = 1.0
Best fit:Δm2
atm = 2.5×10-3 eV2
sin22θatm = 1.0
Confirmed by
•MACRO (Gran Sasso)
•Soudan (USA)
•K2K acceleratorlong baseline(250 km) experiment
•MINOS (USA) acc. exp. in 2006
Sudbury Neutrino ObservatorySNOcharged current interaction (cc)
νe + D −> p + p + eneutral current interaction (nc)
νx + D −> νx + p + nelastic Neutrino-Electron scattering (cc
+ nc)
νx + e −> νx + e 1kt Cherenkov Detectorwith heavy water
SNO Result
• Flavour transitiondiscovered: 7 sigma !
• Reasonableagreement with solar model
Neutrinos from the Sun (νe) transform into νμ or ντ !
Solar Neutrino Oscillation
• Determination of Θ12 ~ 340
νe νμ,τ
Δm2 ~ 8 x 10-5 eV2
• Confirmation by reactorexperiment KamLAND
The solar matter effect – evidence by GALLEX/GNO
GALLEX/GNO
SNO
• Evidence for matter effect inside the Sun
• m2 > m1
• Why are neutrino masses so small?
• GUT
• Leptogenesis
Survival probability electronneutrino
pp- 7Be
8B
Future of Solar Neutrino Spectroscopy: low energies
• Monoenergetic 7Be • CNO, pepWhy?• Accurate Measurement of thermo nuclear
fusion processes:7Be ~ 10% => pp ~ 1% !
• CNO important for star development
The MSW Effect and newPhysics ?
Friedland, Lunardini, Peña-Garay, hep-ph/0402266
The MSW effect as filter
• Θ13
•sterile Neutrinos?
• magnetic Neutrino moment?
• new interactions ?
16L. Oberauer, TU München
Borexino @ Gran Sasso• 7Be solar neutrino measurement
• neutrino electron scattering
• CNO and pep neutrinos
• Long baseline reactor neutrinos
• Terrestrial neutrinos
• Supernova neutrinos
• Search for neutrino magnetic moment
First neutrino events in BOREXINO
Time of flight (CERN to LNGS) ~ 2.4 ms equivalent to ~ 730 km distance
Future Neutrino ObservatoriesUnsegmented50 kt liquid scintillatorLENA
HyperKamiokande (1 MtWater Cherenkov)
…Liquid Argon ~100 ktTPC
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 detectors (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
Extremely Large Observatories
Km3 Cherenkov detector in the mediterranian sea
Km3 Cherenkovdetector at the South Pole (Ice Cube)
Amanda
Frejus
Eν ∝ E-3.8
A change in the slope would indicate a non-atmospheric component
Atmospheric neutrino Waxmann-Bahcall limit: Model-independent upper bound
= 2π = 00-03 combined
Limits from Amanda
Ice-Cube ~ 3 10-9