Related papers: On positronium states in ${\rm{QED_3}}$
The self consistent version of the density functional theory is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems. An exact functional equation for the effective interaction, from…
Bound state problem in the relativistic QED is investigated by the functional integral methods. The ortho- para- positron mass difference is calculated. Contribution of the "nonphysical"$~$ time variable turned out to be important and leads…
Positrons bind to molecules leading to vibrational excitation and spectacularly enhanced annihilation. Whilst positron binding energies have been measured via resonant annihilation spectra for $\sim$90 molecules in the past two decades, an…
Measurements of energy separations in highly charged ions can in many cases nowadays be performed with very high accuracy, an accuracy that sometimes cannot be matched by the corresponding theoretical calcula- tions. Furthermore, it has…
We solve the Schr\"odinger equation with a position-dependent mass (PDM) charged particle interacted via the superposition of the Morse and Coulomb potentials and exposed to external magnetic and Aharonov-Bohm (AB) flux fields. The…
We present a method which computes many-electron energies and eigenfunctions by a full configuration interaction which uses a basis of atomistic tight-binding wave functions. This approach captures electron correlation as well as atomistic…
The energy levels of the muonium ($\mu^+ e^-$) atom, which consists of two ''point-like'' leptonic particles, can be calculated to very high accuracy in the framework of bound state Quantum Electrodynamics (QED), since there are no…
A model-potential approach has been developed to study positron interactions with molecules. Binding energies and annihilation rates are calculated for positron bound states with a range of alkane molecules, including rings and isomers. The…
The bound state spectra of the doublet states in three-electron atomic systems are investigated. By using different variational expansions we determine various bound state properties in these systems. Such properties include the…
We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the…
A functional $E_{xc}[\rho(\r,\epsilon)]$ is presented, in which the exchange and correlation energy of an electron gas depends on the local density of occupied states. A simple local parametrization scheme is proposed, entirely from first…
Positronium, the electron-positron bound state, is described to a good approximation by pure QED. The states of positronium have definite values of C and P. Consequently, positronium is an attractive system for the investigation of possible…
We report bound state solutions of the Klein Gordon equation with a novel combined potential, the Eckart plus a class of Yukawa potential, by means of the parametric Nikiforov-Uvarov method. To deal the centrifugal and the coulombic…
We present the first numerically exact study of self-trapped, a.k.a. soliton, states of electrons that form in materials with strong quadratic coupling to the phonon coordinates. Previous studies failed to observe predictions based on the…
We compute the ground state energy of atoms and quantum dots with a large number N of electrons. Both systems are described by a non-relativistic Hamiltonian of electrons in a d-dimensional space. The electrons interact via the Coulomb…
Electron-electron correlation forms the basis of difficulties encountered in many-body physics. Accurate treatment of the correlation problem is likely to unravel some nice physical properties of matter embedded in the correlation. In an…
The orthopositronium decay to three photons is studied in the phase-space region where one of the photons has an energy comparable to the relative three-momentum of the e+e- system (w ~ m alpha). The NRQED computation in this regime shows…
Fine-tuning of the binding energies and widths of the quasi-bound states in three-body systems consisting of antikaon(s) and nucleon(s) was performed. Dynamically exact three-body Faddeev-type AGS equations with three coupled particle…
We investigate energy correlators in semi-inclusive electron-positron annihilation as precision probes of parton hadronization dynamics. Using soft-collinear effective theory, we analyze the correlation patterns between the examined hadron…
Mijnarends et al. [J. Phys. Condens. Matter {\bf 10}, 10383 (1998)] contested the best existing calculations of positron annihilation rates in jellium and crystal lattices, pointing in this way at deficiencies of existing theories of…