Neutrino mass limit from tritium β decay

Abstract

The paper reviews recent experiments on tritium beta spectroscopy searching\nfor the absolute value of the electron neutrino mass $m(\\nu_e)$. By use of\ndedicated electrostatic filters with high acceptance and resolution, the\nuncertainty on the observable $m^2(\\nu_e)$ has been pushed down to about 3\neV$^2$. The new upper limit of the mass is $m(\\nu_e) < 2$ eV at 95% C.L. In\nview of erroneous and unphysical mass results obtained by some earlier\nexperiments in beta decay, particular attention is paid to systematic effects.\nThe mass limit is discussed in the context of current neutrino research in\nparticle- and astrophysics. A preview is given of the next generation of beta\nspectroscopy experiments currently under development and construction; they aim\nat lowering the $m^2(\\nu_e)$-uncertainty by another factor of 100, reaching a\nsensitivity limit $m(\\nu_e) < 0.2$ eV.\n