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The self-consistent Green's functions method is employed to study the spectroscopic factors of quasiparticle states around ^16,28O and ^40,60Ca. The Faddeev random phase approximation (FRPA) is used to account for the coupling of particles with collective excitation modes. Results for ¹⁶O are reviewed first. The same approach is applied to isotopes with large proton-neutron asymmetry to estimate its effect on spectroscopic factors. The results, based on the chiral N3LO force, exhibit an asymmetry dependence similar to that observed in heavy-ion knockout experiments but weaker in magnitude.

There has been significant progress in the ab initio approaches to the structure of light nuclei. One such method is the ab initio no-core shell model (NCSM). Starting from the realistic two- and three-nucleon interactions, this method can predict the low-lying levels in p-shell nuclei. It is a challenging task to extend the ab initio methods to describe nuclear reactions. In this contribution, we present a brief overview of the NCSM with examples of recent applications as well as the first steps taken toward nuclear reaction applications.

In this paper, the $({}^3\mathrm{\text{He}},d)$ reactions are revisited, with the goal of obtaining spectroscopic factors (SF) for the transition to the ground state of some residual nuclei, applying the distorted wave Born approximation (DWBA). The double-folding São Paulo Potential (SPP) was used to derive the distorted wave function in the entrance and exit channels. The derived SF are compared with the results of extensive shell model calculations showing a rather good agreement.

Beyond the shape phase transition from the spherical vibrator to the deformed rotor regime at $N=90$, the interplay of $\beta$- and $\gamma$-degrees of freedom becomes important, which affects the relative positions of the $K^{\pi }=0^{+}\beta$- and $K^{\pi }=2^{+}\gamma$-bands. In the microscopic approach of the dynamic pairing plus quadrupole model, a correlation of the strength of the quadrupole force and the formation of the $\beta$- and $\gamma$-bands in ${}^{158}$Dy is described. The role of the potential energy surface is illustrated. The $E2$ transition rates in the lower three $K$-bands and the multi-phonon bands with $K^{\pi }=0^{+},2^{+}$ and $4^{+}$ are well reproduced. The absolute $B(E2,2_{\mathrm{\text{i}}}^{+}=0_2^{+})$$(i=2,3)$ serves as a good measure of the quadrupole strength. The role of the single particle Nilsson orbits is also described.

A quantitative calculation of the state-dependent pairing gap requires to go beyond the quasiparticle approximation, treating in detail the breaking of the single-particle strength (self-energy processes), and the induced interaction arising from the exchange of (QRPA) collective vibrations between pairs of nucleons, not to mention the vertex-corrections. Different Skyrme forces have been used for the HF basis to obtain different level densities at the Fermi energy, and special attention has been paid to the calculation of spectroscopic factors with the comparison with the (rather old) existing data. The agreement is encouraging, but the need of new data will be discussed.

Mention will be done of two other important works, discussing the relation of the typical induced-interaction matrix elements with those of the Gogny force and of the v_low-k nucleon-nucleon potential, and pointing-out also in finite nuclei the (relatively small) screening effect of the exchange of spin modes in the induced interaction.

Experimental data describing elastic scattering of nucleons on Ca isotopes are employed to construct the nucleon self-energy at positive energies for these systems using a dispersive optical model analysis. Data below the proton Fermi energy, obtained from the (e, e′p) reaction and the energies of low-lying single-particle orbits are employed to complete the determination of the nucleon self-energy in a broad energy domain that includes a few hundred MeV above and below the Fermi energy. The present analyis allows an extrapolation to larger nucleon asymmetry δ that demonstrates that protons should become more correlated with increasing δ.

Single-particle transfer reactions are typically measured at energies where only a peripheral reaction can occur, without probing the interior of the nuclear wave function. At low energies (≈5 MeV/u), spectroscopic factors cannot be reliably extracted without a detailed description of the bound-state potential. Mukhamedzhanov and Nunes have proposed a method to constrain the shape of the bound state potential by combining transfer reaction measurements at two different energies. The external contribution of the wave function is extracted using a peripheral reaction, and is combined with a higher energy measurement which probes the nuclear interior more deeply. These two measurements should constrain the single-particle asymptotic normalization coefficient, ANC, and enable spectroscopic factors to be deduced with uncertainties dominated by the cross-section measurements rather than the bound-state potential. Published measurements of ⁸⁶Kr(d,p) at 5.5 MeV/u were used to determine the external contribution of this reaction. At less-peripheral energies, ⁸⁶Kr(d,p) at 35 MeV/u has been measured in inverse kinematics at the NSCL using the OR- RUBA and SIDAR arrays of silicon strip detectors. Preliminary analysis shows that the single-particle ANC can be constrained. The details of the analysis and prospects for measurements with neutron-rich beams will be presented.

Recent activity in superallowed isospin-symmetry-breaking correction calculations has prompted interest in experimental confirmation of these calculation techniques. The shellmodel set of Towner and Hardy (2008) include the opening of specific core orbitals that were previously frozen. This has resulted in significant shifts in some of the δ_C values, and an improved agreement of the individual corrected values with the adopted world average of the 13 cases currently included in the high-precision evaluation of V_ud. While the nucleus-to-nucleus variation of is consistent with the conserved-vector-current (CVC) hypothesis of the Standard Model, these new calculations must be thoroughly tested, and guidance must be given for their improvement. Presented here are details of a experiment, undertaken to provide such guidance.

The cadmium isotopes have been cited as excellent examples of vibrational nuclei for decades, with multi-phonon quadrupole, quadrupole-octupole, and mixed-symmetry states proposed. From a variety of experimental studies, a large amount of spectroscopic data has been obtained, recently focused on γ-ray studies. In the present work, the single-particle structure of ¹¹²Cd has been investigated using the reaction. The investigation was carried out using a 22 MeV beam of polarized deuterons obtained from the Maier-Leibnitz Laboratory at Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 115 levels have been identified up to 4.2 MeV of excitation energy. Spin-parity has been assigned to each analyzed level, and angular distributions for the reaction cross sections and analyzing powers were obtained. Many additional levels have been observed compared with the previous (d,p) study performed with 8 MeV deuterons,¹ including strongly populated 5⁻ and 6⁻ states. The former was previously assigned as a member of the quadrupole-octupole quintuplet, based on a strongly enhanced B(E2) value to the 3⁻ state, but is now re-assigned as being predominately s_1/2 ⊗ h_11/2 configuration.