Convergence in the no-core shell model with low-momentum two-nucleon interactions

Understand

The convergence of no-core shell model (NCSM) calculations using renormalization group evolved low-momentum two-nucleon interactions is studied for light nuclei up to Li-7.

• Because no additional transformation was used in applying the NCSM framework, the energy calculations satisfy the variational principle for a given Hamiltonian.
• Dramatic improvements in convergence are found as the cutoffs are lowered.
• The renormalization group equations are truncated at two-body interactions, so the evolution is only approximately unitary and converged energies for A > 2 vary with the cutoff.