Neutrino Mass from the Beta Spectrum in the Decay of Tritium

Abstract

The data from the spectrum measurement of the tritium decay in a valine molecule carried out in a wide energy range (3.4 keV) with the Institute of Theoretical and Experimental Physics spectrometer are analyzed. The combined analysis of both these data and the data of the previous cycle gives the neutrino mass ${30.3}_{-8\mathrm{}}^{+2\mathrm{}}$ eV. The model-independent mass interval $17<\mathrm{}{M}_{\nu }<40\mathrm{}$ eV is derived from the mass difference of the doublet ${}_{}{}^3{}_{}{}^{}\mathrm{H}$-${}_{}{}^3{}_{}{}^{}\mathrm{He}$.