FBS - Few Body Systems

Methods for ab initio accurate solutions of the quantum-mechanical few-body problem are developed. Particular attention is devoted to the most problematic continuum part of the nuclear Hamiltonian spectrum. The aim is to help rooting nuclear dynamics into Quantum Chromo-Dynamics, by comparing the results with new data on stable and exotic systems.

The Science

The ab initio description of nuclei (and other baryon systems) represents a difficult challenge. Their dynamics is ruled mainly by the strong interaction, whose fundamental theory is Quantum Cromo-dynamics (QCD). In practice, however, accounting or predicting the phenomenology of such systems starting from QCD is very hard and still in a semi-qualitative status. Fortunately, due to a clear separation of scales ground state observables and low-energy spectra can be described as a collection of "structureless" particles (protons, neutrons, hyperons etc.) interacting through mutual forces. The accurate form of these forces and their connections to QCD is one of the main goal of modern Nuclear Physics. The present project is directly connected to this problem. The calculation of observables for nuclei seen as a number of interacting nucleons implies the solution of the Schroedinger equation. This becomes more and more complicated as this number increases and it is still largely unsolved in the continuum part of the spectrum. The first goal of the "Few-Body Systems" (FBS) project is to devise better and better methods and numerical techniques, for an accurate solution of the Schroedinger equation, given any force as input. Only a comparison to data of theoretical results, supplied with controllable errors, allows to validate the input force. With validated forces and benchmarked accurate methods devised to calculate observables one can explain/predict various reactions (fusion, radioactive decay, breakups, neutrino cross sections...). Only in this way nuclear physics can give important contributions to a variety of problems/applications like understanding fundamental symmetries, search of "unknown" particles as dark matter, production of exotic nuclei, astrophysical problems (star evolution, neutron star structure, element abundances...), nuclear magnetic resonances, hadron-therapy etc...


• Involved external institutions: TRIUMF (Canada), Hebrew University Jerusalem (Israel), Kurchatov Centre Moscow (Russia)
• INFN groups: Pisa, Padova, Lecce, TIFPA
• Principal Investigator: Michele Viviani (Pisa)
• INFN Project: CSN IV
• Duration: n/a


• Local responsible for TIFPA: Giuseppina Orlandini
• Involved TIFPA people: Winfried Leidemann, Sergio Deflorian, Fabrizio Ferrari Ruffino