We perform no-core full configuration calculations for a set of light nuclei including 16 O with a realistic NN interaction, JISP16. We obtain ground-state energies and their uncertainties through exponential extrapolations that we demonstrate are reliable in 2 H, 3 H, and 4 He test cases where fully converged results are obtained directly. We find that 6 He, 6 Li, and 8 He are underbound by about 600 keV, 560 keV, and 1.7 MeV, respectively. 12 C is overbound by about 1.7 MeV and 16 O is overbound by about 16 MeV. The first excited 0 + states in 12 C and 16 O are also evaluated but their uncertainties are significantly larger than the uncertainties for the ground states.

Fully-microscopic No-core Shell Model (NCSM) calculations of all stable s and p shell nuclei are used to determine a realistic N N interaction, JISP16, describing not only the two-nucleon data but the binding energies and spectra of nuclei with A ≤ 16 as well. The JISP16 interaction, providing rapid convergence of the NCSM calculations, is obtained in an ab exitu approach by phase-equivalent transformations of the JISP6 N N interaction. To complement the successful but computationally intensive 'ab initio' No-core Shell Model (NCSM) [1], we introduce the 'ab exitu' NCSM. While the former has proven very successful for light nuclei when one includes three-body (N N N ) forces [2,3], the computational complexity motivates us to introduce an approach that simultaneously minimizes N N N forces while providing more rapid convergence with a pure nucleon-nucleon (N N ) force. We invoke directly an end-goal of nuclear theory (hence the term 'ab exitu'), a successful description of nuclear properties, including the available N N data, to develop a new class of N N potentials that provide accurate descriptions of a broad range of nuclear data. PACSTo achieve this, we form a union of two recent techniques -the J-matrix inverse scattering [4,5,6] and the NCSM [1]. A major ingredient of our approach is the form of the N N interaction (a small matrix in the oscillator basis), which is chosen to provide rapid convergence of manybody observables within the NCSM. Indeed, we show below that results up through A = 16 obtained directly with the bare interaction (one that accurately describes the N N data) are close to those obtained with the effective interaction and are very useful to establish the confidence region for the binding energy.Since this is a departure from the more traditional approach, we motivate our development with observations concerning the successful ab initio approaches to light nuclei. Indeed several promising microscopic approaches have been introduced and tested extensively with realistic N N interactions (see [7] and references therein) and with realistic N N + N N N interactions [8,2,3]. Progress towards heavier nuclei appears limited only by scientific manpower and by available computers. However, all approaches face the exponentially rising computational complexity inherent in the quantum many-body problem with increasing particle number and novel schemes are needed to minimize the computational burden without sacrificing realism and precision.The earliest and most successful in reaching nuclei beyond A = 4 is the Green's-function Monte Carlo (GFMC) approach [8] whose power has been used to determine a sequence of everimproving N N N interactions [8,9,10], in conjunction with highly precise N N interactions [11] that 1

The nucleon-nucleon interaction is constructed by means of the J-matrix version of inverse scattering theory. Ambiguities of the interaction are eliminated by postulating tridiagonal and quasi-tridiagonal forms of the potential matrix in the oscillator basis in uncoupled and coupled waves, respectively. The obtained interaction is very accurate in reproducing the N N scattering data and deuteron properties. The interaction is used in the no-core shell model calculations of 3 H and 4 He nuclei. The resulting binding energies of 3 H and 4 He are very close to experimental values.