September 15, 2014 to October 10, 2014
Nordita, Stockholm
Europe/Stockholm timezone

No-Core CI calculations of light nuclei: Emergence of rotational bands

Sep 17, 2014, 11:40 AM
40m
f (Nordita, Stockholm)

f

Nordita, Stockholm

Speaker

Pieter Maris

Description

The atomic nucleus is a self-bound system of strongly interacting nucleons. In No-Core Configuration Interaction (CI) calculations, the nuclear wavefunction is expanded in a basis of Slater Determinants of single-nucleon wavefunctions (Configurations), and the many-body Schrödinger equation becomes a large sparse matrix problem. The challenge is to reach numerical convergence to within quantifiable numerical convergence to within quantifiable numerical uncertainties for physical observables using finite truncations of the infinite-dimensional basis space. I discuss the (dis)advantages of different truncation schemes, as well as strategies for constructing and solving the resulting large sparse matrices of current multi-core computer architectures. Several of these strategies have been implemented in the code MFDn, a hybrid MPI/OpenMP Fortran code for ab-initio nuclear structure calculations that has been demonstrated to scale to over 200,000 cores. Finally, I present results for ground state energies, excitation spectra, and select electromagnetic observables for light nuclei in the A=6 to 14 range using realistic 2- and 3-body forces. In particular, I demonstrate that collective phenomena such as rotational band structures can emerge from these microscopic calculations.

Presentation materials