Motivated by a recent analysis which presents explicitly the general solution, we consider the eigenvalue problem of the spinless Salpeter equation with a (“hard-core amended”) Coulomb interaction potential in one dimension. We prove the existence of a critical coupling constant (which contradicts the assertions of the previous analysis) and give analytic upper bounds on the energy eigenvalues....

We study the solutions for a one-dimensional electrostatic potential in the Dirac equation when the incoming wave packet exhibits the Klein paradox (pair production). With a barrier potential we demonstrate the existence of multiple reflections (and transmissions). The antiparticle solutions which are necessarily localized within the barrier region create new pairs with each reflection at the p...

A relativistic equation is deduced for the bound state of two particles, by assuming a proper boundary condition for the propagation of the negative-energy states. It reduces to the (one-body)Dirac equation in the infinite limit of one of the constituent mass. It also has the symmetries to assure the existence of the anti-bound-state with the same mass. The interaction kernel(pseudo-potential) ...

We study the electron-positron system in a strong magnetic field using the differential BetheSalpeter equation in the ladder approximation. We derive the fully relativistic two-dimensional form that the four-dimensional Bethe-Salpeter equation takes in the limit of asymptotically strong constant and homogeneous magnetic field. An ultimate value for the magnetic field is determined, which provid...

We formulate a parity-mixed coupled-cluster (PM-CC) approach for high-precision calculations of parity non-conserving amplitudes in mono-valent atoms. Compared to the conventional formalism which uses parity-proper (PP) one-electron orbitals, PM-CC method is built using (PM) orbitals. The PM orbitals are obtained by solving Dirac-Hartree-Fock equation with electron-nucleus electroweak interacti...

The photoconductance of poiycrystaHine silicon films at photon energies smaller than the band gap has been measured as a function of intensity applying a 1.3 pm wavelength semiconductor laser. The observed photosignaI increases superlinearly at low intensities and saturates above about 1.5 W / em 2. This distinct nonlinearity is caused by a significant energy dependence of optical to thermal cr...

In quantum theory, bound states are described by eigenvalue equations, which usually cannot be solved exactly. However, some simple general theorems allow to derive rigorous statements about the corresponding solutions, that is, energy levels and wave functions. These theorems are applied to the prototype of all relativistic wave equations, the spinless Salpeter equation. PACS : 11.10.St, 03.65...

The Dirac equation in (1+1) dimensions with a non-local PT symmetric potential of separable type is studied by means of the Green function method: properties of bound and scattering states are derived in full detail and numerical results are shown for a potential kernel of Yamaguchi type, inspired by the treatment of low-energy nucleonnucleon interaction. PACS:03.65.CGe, 03.65.Nk, 03.65.Pm, 11....