Ab initio calculations of low-energy nuclear scattering using confining potential traps
Ab initio nuclear structure calculations that compute nuclear static properties based on underlying NN interactions and three-nucleon forces have now progressed to studying medium-mass nuclei. However, first-principle calculations for nuclear scattering/reactions are still limited to light systems. A method suitable for heavier nuclei would be valuable for studying scattering/reactions with astrophysical relevance and for the coming FRIB program's success focusing on unstable nuclei near drip lines.
In this talk, I will present our recent development of such a method (2004.13575 and 1905.05275). It is similar in spirit to the so-called Luscher method, used in Lattice QCD for computing hadronic scattering. The key idea is a computational experiment: realizing the trapping of nucleus-nucleus or nucleus-nucleon systems in a harmonic potential well within the ab initio spectrum calculations, and then extracting scattering information from the output. I will discuss the formalism and report encouraging results from my collaboration with ab initio groups on computing neutron--alpha and neutron--Oxygen-24 scattering phase shifts. I will then switch to our recently developed emulators (2007.03635), which simulate the full solution of few-body scattering and reactions. These emulators open up one exciting way to generalize the presented ab initio approach to the case of three-cluster systems.