Gamma-widths, lifetimes and fluctuations in the nuclear quasi-continuum

Statistical gamma-decay from highly excited states is determined by the nuclear level density (NLD) and the gamma-ray strength function (gamma SF). These average quantities have been measured for several nuclei using the Oslo method. For the first time, we exploit the NLD and gamma SF to evaluate the gamma-width in the energy region below the neutron binding energy, often called the quasi-continuum region. The lifetimes of states in the quasi-continuum are important benchmarks for a theoretical description of nuclear structure and dynamics at high temperature. The lifetimes may also have impact on reaction rates for the rapid neutron-capture process, now demonstrated to take place in neutron star mergers.