Global Microscopic Description of Nucleon-Nucleus Scattering with Quantified Uncertainties

We develop for the first time a microscopic global nucleon-nucleus optical potential with quantified uncertainties suitable for analyzing nuclear reaction experiments at next-generation rare-isotope beam facilities. Within the improved local density approximation and without any adjustable parameters, we begin by computing proton-nucleus and neutron-nucleus optical potentials from a set of five nuclear forces from chiral effective field theory for 1800 target nuclei in the mass range 12 < A < 242 for energies between 0 MeV < E < 150 MeV. We then parameterize a global optical potential for each chiral force that depends smoothly on the projectile energy as well as the target nucleus mass number and isospin asymmetry. Uncertainty bands for elastic scattering observables are generated from a full covariance analysis of the parameters entering in the description of our global optical potential and benchmarked against existing experimental data for stable target nuclei. Since our approach is purely microscopic, we anticipate a similar quality of the model for nucleon scattering on unstable isotopes.

Automated summary

Researchers have developed a microscopic global nucleon-nucleus optical potential, utilizing an improved local density approximation and modeling with five nuclear forces. The study provides an analysis tool for next-generation rare-isotope beam experiments, with successful computation of optical potentials for 1800 target nuclei without using any adjustable parameters. The uncertainty bands for elastic scattering were generated to handle potential experimental errors.