原子核理論研究室

Date/Time: June 8 (Mon), 13:45 pm-

Place: B214 (Institute of Natural Sciences, Univ. of Tsukuba)

Lecturer:  Panagiota PAPAKONSTANTINOU (Institute for Basic Science, Rare Isotope Science Project)

Title: Beyond the mean-field picture, with realistic nuclear interactions

Abstract:

In the past decades, energy-density functional methods have advanced greatly the field of nuclear structure. They have allowed a microscopic and unified description of many properties in medium-mass and heavy nuclei, from masses and sizes to giant resonances, as well as nuclear matter. Known issues include the poorly constrained time-odd terms and the concept of non-linear density dependencies. Fitting the free parameters on the mean-field level means, moreover, that double counting of unknown effects is inevitable in beyond-mean-field applications. In this talk I will present an effort to describe nuclear properties, starting from microscopic NN(N) Hamiltonians, which allows for systematic and controlled extensions of mean-field theory, and can thus be applied in heavy nuclei. The Hamiltonians are first softened via unitary transformations. They can describe nuclear ground states within perturbation theory. They are then applied in linear response theory, namely the random phase approximation and its extensions, to study giant resonances and other vibrational modes. This line of work bridges strictly ab initio methods, restricted to very low energies and light nuclei, and more phenomenological, traditional approaches. It exploits nsights from both and could help them advance in tandem.