Related papers: p-$^3$He Effective Potentials based on the Pauli C…
We apply the renormalisation group (RG) to analyse scattering by short-range forces in systems with coupled channels. For two S-wave channels, we find three fixed points, corresponding to systems with zero, one or two bound or virtual…
Results of large-basis shell-model calculations for nuclei with A=7-11 are presented. The effective interactions used in the study were derived microscopically from the Reid93 potential and take into account the Coulomb potential as well as…
In calculating the energy corrections to the hydrogen levels we can identify two different types of modifications of the Coulomb potential $V_{C}$, with one of them being the standard quantum electrodynamics corrections, $\delta V$,…
We study the $^6$He Borromean nucleus in coordinate representation within a three-body model with two-body potentials derived from cluster effective field theory (EFT). These potentials are originally developed in momentum space and Fourier…
We formulate two methods to facilitate the calculation of perturbative corrections to quantum few-body observables. Both techniques are designed for a numerical realization in combination with any tool that obtains either the entire…
We study halo nuclei using a two-frequency shell-model approach employing wave functions of two different oscillator constants $\hbar\omega_{in}$ and $\hbar\omega_{out}$, the former for the inner orbits and the latter for the halo (outer)…
We construct a coordinate-space potential based on pionless effective field theory with a Gaussian regulator. Charge-symmetry breaking is included through the Coulomb potential and through two- and three-body contact interactions. Starting…
We present a 3D isotropic ab initio three-body (para-H$_2$)$_3$ interaction potential energy surface (PES). The electronic structure calculations are carried out at the correlated coupled-cluster theory level, with single, double, and…
The compressibility of a two-dimensional electron system with spin in a spatially correlated random potential and a quantizing magnetic field is investigated. Electron-electron interaction is treated with the Hartree-Fock method. Numerical…
We have studied the d-wave pairing-instability in the two-dimensional Holstein-Hubbard model at the level of a full fluctuation exchange approximation which treats both Coulomb and electron-phonon (EP) interaction diagrammatically on an…
The low-momentum effective interaction $V_{low k}$ has been formulated in the three-dimensional momentum-helicity representation as a function of the magnitude of momentum vectors and the angle between them. As an application, AV18…
Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel $\pi N \rightarrow \eta N$ is included…
These lectures are centered around a specific problem, the effect of weak repulsive interactions on the transition temperature $T_c$ of a Bose gas. This problem provides indeed a beautiful illustration of many of the techniques which have…
The potential energy surface (PES) describing the interactions between $\mathrm{Li_{2}(^{1}\Sigma_{u}^{+})}$ and $\mathrm{^{4}He}$ and an extensive study of the energies and structures of a set of small clusters, $\mathrm{Li_{2}(He)_{n}}$,…
We study the electronic resonant states of H3 with energies above the potential energy surface of the H3+ ground state. These resonant states are important for the dissociative recombination of H3+ at higher collision energies, and previous…
The $n+{}^3$H, $p+{}^3$He, $p+{}^3$H, and $n+{}^3$He elastic and charge exchange reactions at low energies are studied by means of the hyperspherical harmonic method. The considered nuclear Hamiltonians include modern two- and three-nucleon…
Recent experiments on the laser-induced resonant annihilation provide a precise measurement of transition energies of antiprotonic helium atoms. Relativistic corrections of an order of $\alpha ^2$ to the pure Coulomb interaction will be…
The large variety of experimental data around the pion-production threshold are compared with a meson-exchange isobar model which includes the pion-nucleon interaction in s-- and p-waves. Theoretical results obtained with two different NN…
Low energy antiprotons offer excellent opportunities to study properties of fundamental forces and symmetries in nature. Experiments with them can contribute substantially to deepen our fundamental knowledge in atomic, nuclear and particle…
We numerically study the collective excitations present in isotropic superconductors including a screened Coulomb interaction. By varying the screening strength, we analyze its impact on the system. We use a formulation of the effective…