COMMENTS ON THE NEW NEUTRINO "BALANCE": A DISCUSSION OF THE FEASIBILITY OF USING THE ELECTRON CAPTURE PROCESS IN158Tb, 157Tb FOR NEUTRINO MASS DETERMINATION

It is found that owing to the large energy difference in K-and L-shells of the daughter atom, ¹⁵⁸Tb is not the best candidate for neutrino "balance". Instead, ^l57Tb can offer a better chance for. neutrino mass determination if the Q-value 55 far obtained is verified. If it is so,then the relevant atomic calculation with high precision is very necessary. It is shown that to include the radiative correction in the Hartree-Fock calculation is very important for such atoms as ¹⁵⁷Gd and ¹⁵⁷Tb.