Casali, N; Nagorny, SS; Orio, F; Pattavina, L; Beeman, JW; Bellini, F; Cardani, L; Dafinei, I; Di Domizio, S; Di Vacri, ML; Gironi, L; Kosmyna, MB; Nazarenko, BP; Nisi, S; Pessina, G; Piperno, G; Pirro, S; Rusconi, C; Shekhovtsov, AN; Tomei, C; Vignati, M
We report on the first compelling observation of a decay of Eu-151 to the ground state of Pm-147. The measurement was performed using a 6.15 g Li6Eu(BO3)(3) crystal operated as a scintillating bolometer. The Q-value and half-life measured are: Q = 1948.9 +/- 6.9(stat.) +/- 5.1(syst.) keV, and T-1/2 = (4.62 +/- 0.95(stat.) +/- 0.68(syst.)) x 10(18) y. The half-life prediction of nuclear theory using the Coulomb and proximity potentialmodel are in good agreement with this experimental result.