title: Ab initio coupled-cluster effective interactions for the shell model: application to neutron-rich oxygen and carbon isotopes.
abstract: We derive and compute effective valence-space shell-model interactions from ab initio coupled-cluster theory and apply them to open-shell and neutron-rich oxygen and carbon isotopes. Our shell-model interactions are based on nucleon-nucleon and three-nucleon forces from chiral effective-field theory. We compute the energies of ground and low-lying states, and find good agreement with experiment. In particular, our computed 2(+) states are consistent with N = 14,16 shell closures in (22,24)O, and a weaker N=14 shell closure in (20)C. We find good agreement between our coupled-cluster effective-interaction results with those obtained from standard single-reference coupled-cluster calculations for up to eight valence neutrons.
authors.affiliation: Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: G R
authors.initials: GR
authors.lastname: Jansen
authors.affiliation: Deptartment of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27516-3255, USA.
authors.forename: J
authors.initials: J
authors.lastname: Engel
authors.affiliation: Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: G
authors.initials: G
authors.lastname: Hagen
authors.affiliation: TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada.
authors.forename: P
authors.initials: P
authors.lastname: Navratil
authors.affiliation: Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: A
authors.initials: A
authors.lastname: Signoracci