Abstract
The similarity renormalization group (SRG) has been successfully applied to soften interactions for ab initio nuclear calculations. In almost all practical applications in nuclear physics, an SRG generator with the kinetic energy operator is used. With this choice, a fast convergence of many-body calculations can be achieved, but at the same time substantial three-body interactions are induced even if one starts from a purely two-nucleon () Hamiltonian. Three-nucleon () interactions can be handled by modern many-body methods. However, it has been observed that when including initial chiral forces in the Hamiltonian, the SRG transformations induce a non-negligible four-nucleon interaction that cannot be currently included in the calculations for technical reasons. Consequently, it is essential to investigate alternative SRG generators that might suppress the induction of many-body forces while at the same time might preserve the good convergence. In this work we test two alternative generators with operators of block structure in the harmonic oscillator basis. In the no-core shell model calculations for , , and with chiral force, we demonstrate that their performances appear quite promising.
10 More- Received 10 June 2014
- Revised 8 August 2014
DOI:https://doi.org/10.1103/PhysRevC.90.034302
©2014 American Physical Society