A-dependence of the Spectra of the F Isotopes from ab initio Calculations*

Using a succession of Okubo-Lee-Suzuki transformations within the No Core Shell Model (NCSM) formalism [1], we derive an ab initio, non-perturbative procedure for calculating the input for standard shell-model (SSM) calculations within one major shell. We have used this approach for calculating the spectra of the F isotopes from A=18 to A=25, so as to study the A-dependence of the results. In particular, we are interested in seeing if the theoretical input is weak enough, so that a single set of two-body effective interactions can be used for all of the F isotopes investigated. We will present results from SSM calculations based on input obtained with the JISP16 nucleon-nucleon interaction in an initial $4\hbar\Omega$ NCSM basis space. 1. E. Dikmen et al., Phys. Rev. C 91, 064301 (2015).