The anchor-based approach to energy density functional optimization

Nuclear density functional theory (DFT) is one of the most widely used theoretical tools for the description of finite nuclei and neutron stars. Its performance is defined by underlying energy density functionals (EDFs) with a few parameters adjusted to the properties of finite nuclei and nuclear matter. A common difficulty in the DFT framework (both relativistic and nonrelativistic) is that the inclusion of the deformed nuclei in the fitting protocols increases the optimization time dramatically. As a result, the absolute majority of EDFs are fitted by employing only spherical nuclei in the fitting protocols. However, while this results in a good description of spherical nuclei, it reduces the global performance of the EDFs [1, 2]. To alleviate this problem, we propose a new anchor-based approach to the optimization of EDFs. In this approach, the optimization is based on a set of "anchor" spherical nuclei. The binding energies of these nuclei are corrected by minimizing the difference between the calculated and experimental binding energies of all known even-even nuclei. To illustrate the approach's applicability, it has been used to optimize the covariant EDFs and has shown significant global improvements in the description of physical observables [2]. In my presentation, I will discuss this new approach and highlight the main results obtained.