Related papers: Ab initio coupled-cluster theory for open-shell nu…
A one-dimensional harmonic oscillator in a box is used to introduce the oblique-basis concept. The method is extended to the nuclear shell model by combining traditional spherical states, which yield a diagonal representation of the usual…
The binding energies of the ground states and several excited states related to single-particle and -hole states in nuclei around ^{16}O are calculated taking charge dependence into account. Effective interactions on the particle basis are…
A microscopic version of the Continuum Discretized Coupled Channel (CDCC) method is used to investigate $^{6}$He scattering on $^{27}$Al, $^{58}$Ni, $^{120}$Sn, and $^{208}$Pb at energies around the Coulomb barrier. The $^{6}$He nucleus is…
In single-reference coupled-cluster (CC) methods, one has to solve a set of non-linear polynomial equations in order to determine the so-called amplitudes which are then used to compute the energy and other properties. Although it is of…
We discuss strength of monopole excitation of the ground state to cluster states in light nuclei. We clarify that the monopole excitation to cluster states is in general strong as to be comparable with the single particle strength and…
A simple three-body model of 6He is extended to include sd-continuum states in the picture in addition to the already investigated p-states. The role of different continuum components in the weakly bound nucleus 6He is studied by coupling…
We present a study of the two dimensional circular quantum dot model Hamiltonian using a range of quantum chemical ab initio methods. Ground and excited state energies are computed on different levels of perturbation theories including the…
Halo effective field theory (Halo-EFT) has proved to be very efficient for describing halo nuclei within models of nuclear reactions. Its order-by-order expansion scheme enables us to single out the structure observables that are probed in…
The halo nuclei $^6$He and $^8$He are described in a consistent way in a microscopic multiconfiguration model, the refined resonating group method. The ground state properties have been calculated, and momentum distributions of fragments…
The phenomenon of orbital relaxation upon excitation of core electrons is a major problem in the linear-response treatment of core-hole spectroscopies. Rather than addressing relaxation through direct dynamical correlation of the excited…
Two new low-lying $^6$He levels at excitation energies of about 2.4 and 2.9 MeV were observed in the experimental investigation of the p-$\alpha$ coincidence spectra obtained by the $^3$H($^4$He,p$\alpha$)2n four-body reaction at $E_{\rm…
Resonances and continuum states of He isotopes are investigated using the cluster orbital shell model (COSM) with the complex scaling method (CSM). We discuss the following subjects: 1) Spectroscopic factors of the unbound nucleus 7He into…
A new symplectic-based shell-model approach to clustering in atomic nuclei is proposed by considering the simple system $^{20}$Ne. Its relation to the collective excitations of this system is mentioned as well. The construction of the Pauli…
Nuclei at both the neutron- and proton-drip lines are studied. In the cluster-core model, the halo-structure of all the observed and proposed cases of neutron- or proton-halos is investigated in terms of simple potential energy surfaces…
We generalize the coupled-cluster (CC) approach with singles, doubles, and the non-iterative treatment of triples termed $\Lambda$CCSD(T) to Hamiltonians containing three-body interactions. The resulting method and the underlying CC…
The composition of hot and dense nuclear matter is calculated including the $1p$-shell nuclei $4 \le A \le 16$. In-medium shifts, in particular Pauli blocking, are determined by the intrinsic wave function of the nuclei. Results are given…
The possibility of the $^8$He and $^{9}$Li clusters in atomic nuclei is discussed. Until now most of the clusters in the conventional models have been limited to the closures of the three-dimensional harmonic oscillators, such as $^4$He,…
We study the correlations between two neutrons in borromian nuclei $^{11}$Li and $^6$He by using a three-body model with a density-dependent contact two-body interaction. It is shown that the two neutrons show a compact bound feature at the…
We review the latest variational calculations of the ground state properties of doubly closed shell nuclei, from $^{12}$C to $^{208}$Pb, with semirealistic and realistic two- and three-nucleon interactions. The studies are carried on within…
The computational cost of ab initio nuclear structure calculations is rendered particularly acute by the presence of (at least) three-nucleon interactions. This feature becomes especially critical now that many-body methods aim at extending…