Non-accelerator neutrino mass searches

Neutrinos play a fundamental role in several fields of physics from cosmology down to particle physics. Even more, the observation of a non-vanishing rest mass of neutrinos would have a big impact on our present model of particle physics and might guide towards grand unified theories. Currently three evidences exist showing effects of massive neutrinos: the deficit in solar neutrinos, the zenith angle dependence of atmospheric neutrinos and the excess events observed by LSND. These effects are explained with the help of neutrino oscillations, thus depending on ∆m = m2 − m1, where m1, m2 are the neutrino mass eigenvalues and therefore are not absolute mass measurements. For a recent review on the physics of massive neutrinos see .