Big World of Small Neutrinos
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Big World of Small NeutrinosBig World of Small Neutrinos
Roman ShcherbakovRoman Shcherbakov21, March, 200721, March, 2007
3 Nobel prizes3 Nobel prizes
1988 1988 LEDERMAN,LEDERMAN, SCHWARTZ and JACKSCHWARTZ and JACK STEINSTEINBERGBERGERER – – detected muon neutrinosdetected muon neutrinos
1995 REINES – detected reactor neutrinos in 19561995 REINES – detected reactor neutrinos in 1956 2002 2002 RAYMOND andRAYMOND and KOSHIBAKOSHIBA – detected solar neutrinos – detected solar neutrinos
Neutrino opticsNeutrino optics
NS
in the Neutron Star
in the Earth
in the Sun
Neutrino oscillationsNeutrino oscillations
Neutrino oscillationsNeutrino oscillations
Hierarchy is not yet known
Mixing matrix
=>different neutrino & antineutrino
For E=10MeV L12~300km L13~10km
Only 1/3 of born electron neutrino stay electron neutrino
Solar neutrinosSolar neutrinos> 50 trillion solar neutrinos pass through the human body every second
it would take approximately one light year of lead to block half of them
butbut
400kEv
10MEv
Qen e p:decayβAtomrecoil
In the nucleus
B-decay energy spectrumB-decay energy spectrum8
MSW effectMSW effect
Oscillations enforced by scattering
•Not important for the Sun
•Considered in detailed calculations of supernova explosions
Supernova 1987aSupernova 1987a
51kpc away
24 neutrinos
Supernova explosion (type II)Supernova explosion (type II)
Theoretical neutrino spectrumTheoretical neutrino spectrum
Total neutrinoTotal neutrinobackground luminositybackground luminosity
Cosmic neutrino background (CNB)Cosmic neutrino background (CNB)Similar to CMB
Undetectable by any means
Bad dark matter candidate – relativistic in the time of recombination
Cold dark matter is favorable for structure formation
Cuspy halos are not cuspyCuspy halos are not cuspy
2 solutions
• Large annihilation cross-section of cold dark matter (KKT model)
• Warm dark matter
Cold dark matter annihilationCold dark matter annihilation
Doesn’twork
Only decay tosterile particlesIs possible
ConclusionsConclusions
Neutrinos provide a new great tool for:Neutrinos provide a new great tool for: probing the interior of the Sunprobing the interior of the Sun observing the early stages of supernovae observing the early stages of supernovae proving particle theoriesproving particle theories
☺☺☺☺☻☻☻☻