Interaction of neutrino with matter Neutrinos interact only

Interaction of neutrino with matter Neutrinos interact only by weak interaction Weak interaction is mediated by exchange of intermedial bosons: Z 0 (neutral currents) Basic laws for vertexes Examples of weak interaction of neutrinos with hadrons Examples of weak interaction of neutrinos with electrons and W+, W- (charged currents) Charges, lepton numbers, quark flavor and color are not conserved 1) electric charge conserves 2) Lepton number conserves 3) Number of quarks conserves 4) Flavors are not conserved

Example of interaction belonging to neutral currents (anihilation of electron and electron antineutrino) Weak intensity of interaction and their short range are given by large mass of calibration bosons – effective intensity of interaction Range 10 -18 m Weak interaction is in model of electroweak interaction characterized by coupling constant g Connection to Fermi constant GF (E<<MWc 2): Cross-section of reaction in lowenergy limit (Eν << Mpc 2): σ = 5, 8∙ 10 -18 fm 2 → 5, 8∙ 10 -17 mbarn for comparison strong interaction has σ = 3 – 5 fm 2 → 30 – 50 mbarn Property of intensity of interaction with energy for different interaction

Detection methods 1) Inverse beta decay: Proton is not excited → determination of neutrino energy is possible: Capture on heavy nuclei: Eν = Ee + Eod + (En – Ep) Detection of only electron neutrinos or antineutrinos 2) Production of e , μ a τ : follow-up detection of charged leptons and determination of their energies Detection of all neutrino and antineutrino types 3) Scattering on electrons: follow-up detection of reflected electrons Detection of all neutrino and antineutrino types – possibility of detection of neutrino even with very low energies 4) Scattering on nuclei: follow-up detection of deflected nuclei Detection of all neutrino types