Mesures de vies moyennes dans 12B, 14N et 16O

Lifetimes of nuclear states have been measured by the Doppler-shift attenuation method. Gamma radiations from the 11B(d,pγ)12B, 19F(p,αγ)16O, and 12C(h,pγ)14N reactions were observed with a Ge(Li) detector at θγ = 7°, 90° and 173°. The following lifetimes were obtained:Upper limits have been set for very fast lifetimes, and transition energies were also determined. The partial widths of the radiative transitions from the 6.44 MeV state of 14N were compared with theoretical predictions. The amplitude of a (p3/2)−2 configuration in the wave function of this level was evaluated using the partial width of the 6.44 → 3.95 MeV transition determined in the present work.