Atomic effects on neutrino interactions (Paschos, Porfyriadis, G.) ν-ionization of H and noble atoms: atomic effects important for ~10keV ν-energies, but they preserve the basic features of ν-scattering off free electrons at rest.    Paris December 2004 G.J. Gounaris

Basic Interaction For ~14 keV neutrinos, we cannot neglect atomic binding, Paris December 2004 G.J. Gounaris

first ν scattering off free electrons at rest << Paris December 2004 G.J. Gounaris

σ for free electrons (free electron case) < Paris December 2004 G.J. Gounaris

ν free electron spectrum very different shape! Paris December 2004 G.J. Gounaris

anti-ν free electron spectrum very different shape! Paris December 2004 G.J. Gounaris

Ionization of noble atoms (spin ind. wave functions) ( H case) binding energy Paris December 2004 G.J. Gounaris

Atomic wave functions for He, Ne, Ar, Kr, Xe RHF spin-independent wave functions (less accurate for Xe ) http://www.webelements.com/webelements Paris December 2004 G.J. Gounaris

Ne anti-ν ionization e spectra: (accuracy ~2% ) Shape analogous to the free case Paris December 2004 G.J. Gounaris

Xe anti-ν ionization e spectra: (accuracy ~10% ) Paris December 2004 G.J. Gounaris

Integrated ionization cross sections Paris December 2004 G.J. Gounaris

Binding cancels out in ratios ν flavor dep. Binding cancels out in ratios Paris December 2004 G.J. Gounaris

Binding cancels out in ratios anti-ν flavor dep. Binding cancels out in ratios Paris December 2004 G.J. Gounaris

The e-neutrino oscillation = for Paris December 2004 G.J. Gounaris

Room size experiment ! Oscillation lengths = Paris December 2004 G.J. Gounaris

An oscillation picture ~ L(m) Paris December 2004 G.J. Gounaris

Zoom at first 12m L(m) Paris December 2004 G.J. Gounaris

Weinberg angle (Dawson) The E158 SLAC Møller exp finds Paris December 2004 G.J. Gounaris

Measuring Weinberg angle 3% Best closest to source and at low Paris December 2004 G.J. Gounaris

ν e-magnetic moment There exist another two such magnetic operators. Majorana neutrinos: mm always dim=7 operators. There exist another two such magnetic operators. They induce mm not only to γ, but to Z and W also. A Paris December 2004 G.J. Gounaris

ν-electromagnetic effect (Beacom, Fayans, Wong) (if only two mass eigenstates are relevant) Look for enhancement at low ionization electron energies Paris December 2004 G.J. Gounaris

It surpasses reactors also (McLaughlin)… Zνν magnetic effect Induced incoherent contribution to Z width (operator of slide 20) Low energy neutrino ionization is surprisingly more efficient than LEP, in constraining neutrino magnetic moments! It surpasses reactors also (McLaughlin)… I have ignored Dirac neutrinos... Paris December 2004 G.J. Gounaris

Outlook If these ionization cross sections are measurable: Neutrinos at the ~10 keV-energy scale could indeed provide another way to measure Could they supply an independent measurement of the Weinberg angle at a very low energy scale? They may help improving the constraint on the neutrino magnetic moment. Paris December 2004 G.J. Gounaris