We use phase-equivalent transformations to adjust off-shell properties of similarity renormalization group evolved chiral effective field theory NN interaction (Idaho N3LO) to fit selected binding energies and spectra of light nuclei in an ab exitu approach. We then test the transformed interaction on a set of additional observables in light nuclei to verify that it provides reasonable descriptions of these observables with an apparent reduced need for three- and many-nucleon interactions.Comment: Revised text due to journal referee comments. 6 pages, 2 figure

We solve for properties of 6 Li in the ab initio No-Core Full Configuration approach and we separately solve for its ground state and J π = 2 + 2 resonance with the Gamow Shell Model in the Berggren basis. We employ both the JISP16 and chiral NNLOopt realistic nucleon-nucleon interactions and investigate the ground state energy, excitation energies, point proton root-meansquare radius and a suite of electroweak observables. We also extend and test methods to extrapolate the ground state energy, point proton root-mean-square radius, and electric quadrupole moment. We attain improved estimates of these observables in the No-Core Full Configuration approach by using basis spaces up through Nmax = 18 that enable more definitive comparisons with experiment. Using the Density Matrix Renormalization Group approach with the JISP16 interaction, we find that we can significantly improve the convergence of the Gamow Shell Model treatment of the 6 Li ground state and J π = 2 + 2 resonance by adopting a natural orbital single-particle basis.

We perform a quantitative study of the microscopic effective shell-model interactions in the valence sd shell, obtained from modern nucleon-nucleon potentials, chiral N3LO, JISP16 and Daejeon16, using No-Core Shell-Model wave functions and the Okubo-Lee-Suzuki transformation. We investigate the monopole properties of those interactions in comparison with the phenomenological universal sd-shell interaction, USDB. Theoretical binding energies and low-energy spectra of O isotopes and of selected sd-shell nuclei, are presented. We conclude that there is a noticeable improvement in the quality of the effective interaction when it is derived from the Daejeon16 potential. We show that its proton-neutron centroids are consistent with those from USDB. We then propose monopole modifications of the Daejeon16 centroids in order to provide an adjusted interaction yielding significantly improved agreement with the experiment. A spin-tensor decomposition of two-body effective interactions is applied in order to extract more information on the structure of the centroids and to understand the reason for deficiencies arising from our current theoretical approximations. The issue of the possible role of the three-nucleon forces is addressed. nificant progress in ab-initio calculations for light nuclei, the structure of the open-shell medium-mass nuclei can still be described only by restricted valence-space calculations. Thus, the goal to derive effective valence-space interactions represents a major area of endeavor.The present study is focused on the use of the No-Core Shell Model (NCSM) [1] in conjunction with additional theoretical treatment that leads to effective interactions for valence space shell-model calculations. Within the NCSM, all A nucleons, interacting via realistic forces, are treated as active within a model space, consisting of a large number of shells (typically, shells of a harmonicoscillator potential). The eigenvalue problem is solved by diagonalization of the many-body Hamiltonian matrix in a spherically symmetric harmonic-oscillator basis. The many-body eigenstates, represented as mixing of configurations expressed as Slater determinants of the proton and neutron single-particle wave functions, preserve all fundamental symmetries of atomic nuclei and can be used directly to calculate matrix elements of various operators. As a fully ab-initio approach, the NCSM

At the dawn of a new theoretical tool based on the AdS/CFT correspondence for nonperturbative aspects of quantum chromodynamics, we give an interim review on the new tool, holographic QCD, with some of its accomplishment. We try to give an A-to-Z picture of the holographic QCD, from string theory to a few selected top-down holographic QCD models with one or two physical applications in each model. We may not attempt to collect diverse results from various holographic QCD model studies.