Orateur
Description
Despite major advances over recent decades, the origin of the elements heavier than iron remains debated and is not yet fully resolved. In particular, our understanding of the nucleosynthesis processes is still affected by relatively large nuclear uncertainties. Given the extreme scarcity of experimental reaction and decay data for the many unstable nuclei involved in nucleosynthesis processes, theory plays a key role to fill the gaps. For the last decades, nuclear astrophysicists have been trying to estimate the impact of theoretical nuclear uncertainties on astrophysical observables, i.e.
• To improve models and optimize model parameters for the various nuclear inputs entering reaction/decay rates
• To estimate reaction/decay rates and quantify the nuclear uncertainties
• To propagate the nuclear uncertainties into astrophysical simulations and astronomical observables
• To identify the reaction/decay rates impacting the most observables for future (experimental or theoretical) improvements
Theoretically, reaction and decay data of astrophysical interest are calculated starting from nuclear ingredients, such as ground state properties (masses, deformations, densities, …), nuclear level densities, photon strength functions, optical potentials, beta-strength functions and fission properties (fission paths, level densities at saddle points, …). Each of these inputs is affected by both model and parameter uncertainties. The complex challenges in estimating these uncertainties as well as in propagating them to nucleosynthesis simulations will be discussed and illustrated.