Acta Physica Slovaca 53(2003)

A. Nazarenko
Classical relativistic system of pointlike masses with linearized gravitational interaction
Acta Physica Slovaca 53, 1 (2003)
Abstract: The Hamiltonian formulation of relativistic system of pointlike particles with gravitational field is considered within the linearized theory of gravity. Both the Einstein's theory and the gauge theory of gravity are explored. The gaugeinvariant description in the terms of Dirac's observables is obtained. Elimination of physical field variables is performed by means of the Dirac's theory of constraints up to the first order in the gravitational constant. The relation between positional and canonical variables of particles is found.

E. O. Iltan, H. Sundu
Anomalous magnetic moment of the muon in the two Higgs doublet model
Acta Physica Slovaca 53, 17 (2003)
Abstract: We calculate the new physics effects on the anomalous magnetic moment of the muon in the framework of the two Higgs doublet model. We predict an upper bound for the lepton flavor violating coupling, which is responsible for the point like interaction between muon and tau, by using the uncertainty in the experimental result of the muon anomalous magnetic moment. We show that the upper bound predicted is more stringent compared to the one which is obtained by using the experimental result of the muon electric dipole moment.

H. L. Yadav, U. R. Jakhar, K. C. Agarwal
Relativistic meanfield description of Sn isotopes
Acta Physica Slovaca 53, 25 (2003)
Abstract: Recently proposed BCS approach with a discretized continuum (by enclosing the nucleus in a spherical box) for the calculation of pairing energy for the dripline nuclei within the framework of relativistic meanfield (RMF) theory is applied to the description of the ground state properties of Sn isotopes. The TMA parameter set is used for the effective meanfield Lagrangian with the nonlinear terms for the sigma and omega mesons. The results for the two neutron separation energies, and proton and neutron rms radii are shown to be in excellent agreement with the available experimental data and with the recent calculations using the relativistic HartreeBogoliubov (RHB) theory. Also, the calculated neutron single particle pairing gaps are found to be in agreement with the RHB and other meanfield calculations.
 A.S. F. Obada, A. Schreiber, M. AbdelAty
Entropic unceratainty relation of a singletrapped ion interacting with laser beams
Acta Physica Slovaca 53, 37 (2003)
Abstract: In this communication we analyze the quantum motion of an ion isotropically confined in the radial plane of a Paul microtrap when it is irradiated by a properly chosen configuration of external laser beams. We present a derivation of an analytical solution, by means of which we study the entropic uncertainty relation. Using parameters corresponding to existing experimental realization, we have studied the variation effect for the initial total number of vibrational quanta and the phase.

V. Bezak
Minibands in semiconductor superlattices modelled as Dirac combs (significance of band nonparabolicity)
Acta Physica Slovaca 53, 49 (2003)
Abstract: A generalization of the KronigPenney problem is put forward with the potential energy $V(x)=\gamma\sum_j{\delta}(xja)$, $\gamma>0$. A periodic multilayer $\dots$ABABABA$\dots$ is considered: layers A of thickness $a$ are intercalated between layers B of much smaller thickness. In this superlattice, A and B symbolize, respectively, narrowgap semiconductor layers and barrier layers. The conduction band of the semiconductor A is defined by the dispersion function $E({\bf k})$ which was derived in the Kane twoband theory. Owing to the nonzero value of the parameter $\gamma$, the electron energies inside the interval corresponding to the conduction band of the semiconductor A are organized in minibands separated by forbidden gaps. With $E({\bf k})$ taken in the Kane form, the dispersion law ${\cal E}=E({\bf k})$ is nonparabolic if $E_{\rm g}$ (the width of the forbidden gap of the semiconductor A) is finite. This nonparabolicity affects the positions and widths of the minibands. If $E_{\rm g}$ tends to infinity, the original KronigPenney problem is recovered. If $E_{\rm g}$ decreases, the density of the minibands increases.

H. Ritsch, H. A. Hessian
Influence of phase damping in the presence of Stark shift on nonclassical properties of the twomode JCM
Acta Physica Slovaca 53, 61 (2003)
Abstract: In the present communication, we study the influence of phase damping in the presence of Stark shift for the multiquanta JCM, using a master equation describing phase damping under the Markovian approximation. An analytic solution of the master equation for the multiquant twomode JCM Hamiltonian with the phase damping in the presence of Stark shift is obtained. We use this solution to investigate the influence of phase damping and Stark shift on nonclassical properties of the system, for the resonant and the offresonant cases. We compare the behaviour of the system in the case of having a coherent superposition state and a statistical mixture of coherent states as an initial field. Our results show that the Stark shift plays an important role in the evolution of the population inversion in the JCM.

N. Milinski, E. Milinski
Erratum notice
Acta Physica Slovaca 53, iii (2003)
Abstract:
