P. Manakos

Influence of non-central interactions on low lying states of24Mg

Shell model calculations of low lying positive parity states of24Mg have been performed in anSU(3) truncated space. In contrast to previousSU(3) model calculations the experimental spectrum can be reproduced well. This is attained by variation of a certain non-central component of the residual interaction.

Study of low lying states of24Mg

A systematic method for the choice of configurations has been applied toT=0 positive parity states of24Mg. Shell model calculations with central forces have been performed for various truncations of the vector space.

Unitary treatment of infrared singularities

Infrared singularities are treated to all orders by a unitary approximation of the time-evolution operator. The method allows the renormalization of the ultraviolet divergencies. It has been tested in QED bremsstrahlung processes.

Perturbation theory instead of large scale shell model calculations

Results of large scale shell model calculations for (sd)-shell nuclei are compared with a perturbation theory treatment. It is shown that second order perturbation theory provides an excellent approximation when the SU(3)-basis is used as a starting point. The results indicate that perturbation theory treatment in an SU(3)-basis including 2ħω excitations should be preferable to a full diagonalization within the (sd)-shell.

Short note on relativistic Hartree Fock models for nuclei with skyrme type interactions

A manifestly non-renormalizable effective Lagrangian with four fermion coupling is proposed for relativistic Hartree Fock calculations. It is briefly compared with other field theoretic models.

Renormalized Relativistic {Hartree-Fock} Models With Skyrme Type Interactions

A manifestly nonrenormalizable effective Lagrangian with four fermion coupling is proposed for relativistic Hartree Fock calculations. A consistent scheme for the inclusion of the Dirac sea is described in detail. It is briefly compared with other field theoretic models commonly used in nuclear physics.

Leading and subleading logarithmic QCD corrections to bilinear heavy quark currents

We present a complete calculation of the two loop anomalous dimension and the corresponding Wilson coefficient for bilinear currents of heavy quarks.

kronos: A Monte Carlo event generator for higher order QED corrections at HERA — Status report

Abstract We report on the status of the Monte Carlo event generator KRONOS for deep inelastic lepton hadron scattering at HERA. kronos focusses on the description of electronmagnetic corrections beyond the existing fixed order calculations.

Bounds on the coupling parameters for vector mesons in the Relativistic Random Phase Approximation

The Relativistic Random Phase Approximation for a meson-nucleon field theory with vector mesons is cast into an exactly soluble model. This allows to derive bounds on their couplings from consistency conditions without malting use of perturbative expansions. We find that the coupling used to fit low energy properties requires a strong suppression ofN−¯N-states by suitable cut offs.

Relativistic RPA for finite nuclei with Skyrme type interaction

A relativistic RPA is derived starting from a model Lagrangean with four-fermion coupling. The exchange terms are taken exactly into account by exploiting Fierz relations. The model is applied to negative parity states of16O. Exchange terms turn out to give large contributions.