Speakers
Description
How elements are made in the Universe is an open long-standing question. Several processes are invoked to explain the observed elemental abundances in our Solar System [1] and in our Galaxy [2].
Complex simulations of astrophysical events are used to study the origin of the heavy elements and quantify the contribution of the r-process to the observed elemental abundances [3]. This process proceeds through very neutron rich nuclei, most of them experimentally inaccessible so far and theoretical estimates supply the lack of experimental data, introducing large uncertainties in the calculated abundances [4]. The main decay mode of such nuclei is beta-decay accompanied by the emission of one or more neutrons. Accurate experimental data of these nuclei, particularly their half-lives $\mathrm{T}_\mathrm{1/2}$ and neutron emission probabilities $\mathrm{P}_\mathrm{xn}$, will contribute to reduce the uncertainties of the calculated elemental abundances and allow a critical comparison with several nuclear structure models.
The BRIKEN (Beta delayed neutron measurements at RIKEN) collaboration was launched to provide precise new measurements of $\mathrm{T}_\mathrm{1/2}$ and $\mathrm{P}_\mathrm{xn}$ of very neutron rich nuclei which are important for r-process nucleosynthesis [5]. We will report new experimental values from RIBF127 experimental campaign for 39 nuclei between $^\mathrm{75}$Co and $^\mathrm{94}$Br, for which 12 $\mathrm{P}_\mathrm{xn}$ and 7 $\mathrm{T}_\mathrm{1/2}$ are measured for first time and the remaining ones improved. The analysis methods [6] were refined and systematic errors carefully considered in order to improve the accuracy of results. The astrophysical impact in several scenarios was explored and the most relevant cases will be presented.