On the optimum set of polarization measurements for the scattering of two indentical fermions to determine the helicity amplitudes

The polarization asymmetries related to usual polarizations combine at least 4 different helicity amplitudes. The introduction of ±45° inclined transverse polarizations allows us to obtain the complete set of new polarization asymmetries combining only up to 3 helicity amplitudes. There are no further polarization asymmetries depending on a smaller number of helicity amplitudes. These expressions are most economical to determine the helicity amplitudes from observed data. Some of them are suitable to study especially the spin-flip effects. We give a complete Table of all such polarization asymmetries.     

Quantization of collective regular structures of particles

The theory of many-body systems constitutes one of the most complex part of quantum mechanics. Closed results are not readily available and approximations become extremely involved. It is, therefore, of considerable interest that the quantization of certain simple collective motions of particles can describe the energies of atoms, nuclei and particle models rather well. We describe here the most elementary examples of such structures.Dedicated to H. Walther, a great scientist and who demonstrated among many other things the regular shapes of atomic particles, the subject of this essay     

Center-of-mass motion of a system of relativistic Dirac particles

The relativistic center-of-mass motion for a system ofN fermions can be exactly separated because of the linearity of the Dirac operators in momenta which is not possible for quadratic Klein-Gordon particles. The covariant equations derived from Maxwell-Dirac field theory are considered. The center-of-mass equation is still a 4 ^N -component spinor equation. We solve these equations for two- and three-body systems, as well as the relative motion for the non-interacting case, and discuss the quantum numbers and identification of eigenstates and eigenvalues. The results apply for both bound and scattering states. Dedicated to the Third Centenary of the Publication of Principia: Corollary IV.... and therefore the common center of gravity of all bodies acting upon each other (excluding external actions and impediments) is either at rest, or moves uniformly in a right line. Is. Newton, Philosophiae Naturalis Principia Mathematica (S. Pepys, Julii 5, 1686, Londini)     

Nonperturbative quantum electrodynamics: The Lamb shift

The nonlinear integro-differential equation, obtained from the coupled Maxwell-Dirac equations by eliminating the potential A, is solved by iteration rather than perturbation. The energy shift is complex, the imaginary part giving the spontaneous emission. Both self-energy and vacuum polarization terms are obtained. All results, including renormalization terms, are finite.     

The einstein a-coefficient of spontaneous emission: a relativistic calculation in the Heisenberg representation

We present a simple approach to the relativistic calculation of the rates of spontaneous emission starting from the Heisenberg picture formula for the power radiated by a charged particle undergoing acceleration, and evaluate atomic decay rates using relativistic Dirac-Coulomb wavefunctions. The spin of the electron, embedded in its relativistic wavefunction, is shown to correctly provide the two polarization states of the emitted radiation. We discuss selection rules and calculate the Hydrogen 2P → 1S transition rate, among others, to be Γ=(6.2650±0.0007)×10⁸ s^?1 in good agreement with the full field theory calculation as well as with experiment.     

Enamines of 1,3-dimethylbarbiturates and their symmetrical palladium(II) complexes: synthesis,characterization and biological activity

Transition Metal Chemistry - Three 1,3-dimethylbarbiturate-enamine derivatives and their symmetrical palladium(II) complexes were prepared and characterized by spectroscopic methods. In addition,...     

Charge quantization condition withN strings. A new internal quantum number of charge-monopole systems

Dirac theory of magnetic poles is equivalent to a Maxwell electrodynamics in which besides the point singularities (electric charges), extended singularities (e.g. strings) occur. The nature of singularities determine completely the theory, hence Betti numbers of space must occur as quantum numbers. Magnetic charge is one of the fundamental periods of the 2-formF.     

Irreversibility,organization, and self-organization in quantum electrodynamics

QED is a fundamental microscopic theory satisfying all the conservation laws and discrete symmetries C, P, T. Yet, dissipative phenomena, organization, and self-organization occur even at this basic microscopic two-body level. How these processes come about and how they are described in QED is discussed. A possible new phase of QED due to self-energy effects leading to self-organization is predicted.     

Synthesis,characterization, crystal structure,and antimicrobial studies of 2-morpholinoethyl-substituted benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes

Research on Chemical Intermediates - This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and...     

Conformal covariance and the probability interpretation of wave equations

The Dirac and the Schrödinger fields are singled out among all other fields by their conformal dimension $\text{l = ?}\text{3}\text{2}$, a necessary condition for the field to have also a probability interpretation as a wave function. The correct dimension of the Schrödinger field comes about by an intricate contraction of the conformal group to the Schrödinger group.