abstract

We consider lattice systems of continuous spins which correspond to the trigonometric perturbation of the Gaussian superstable two-body interactions. Using some correlation inequalities of the Ginibre type we prove uniqueness of the tempered, translationally invariant Gibbs states whenever the pressure is differentiable at the coupling constant.

abstract

We present a model light front calculation of the inelastic electron-deuteron scattering within the conventional two nucleon approximation. The results lead to the clear interpretation of the convolution formula expressing structure functions of the deuteron by structure functions of nucleons. Several ambiguities of this formula, including the West-\(\beta \) correction and the Bodek ambiguity, are resolved. We use a simple quark model for the nucleon structure, guided by the counting rules. In extracting the neutron structure from the deuteron and the proton data we find that the dynamical off-shell effects in the nucleon structure functions are larger than the properly calculated smearing corrections.

abstract

The Duffin–Kemmer–Petiau equation for a spin-0 or spin-1 particle is interpreted as the point-like limiting case of a new relativistic wave equation for a tight system of two Dirac particles. In the new wave equation, masses of two Dirac particles appear additively, in contrast to the familiar Breit equation where their kinetic energies are additive. From such a two-body relativistic wave equation an equivalent set of radial equations is derived when the internal interaction is described by central potentials. Then it is observed that for a Coulombic internal potential the new wave equation admits no physical solutions corresponding to \(^1\)S\(_0\) states. A possible advantage of this fact for composite models of \(W\) and \(Z\) bosons is pointed out.

abstract

The influence of the observer’s world-line on his concept of the particle is discussed. For a real massless scalar field the creation and annihilation operators are introduced for an observer in a two dimensional curved space-time. The vacuum expectation values of the stress-energy tensor are computed.

abstract

All the electromagnetic formfactors for the massive, Dirac neutrinos are calculated in the frame of the GSW model. Their dependence on the Kobayashi–Maskawa mixing and C, P, T properties are discussed. Three formfactors depend on gauge, the other ones are gauge independent. In the static limit \(q^2 \to 0\), in one loop approximation the Dirac neutrino has two electromagnetic characteristics — the magnetic moment (which vanishes for massless neutrino) and anapole (which is different from zero in the massless limit). Present experimental data do not give possibility to check these static properties of the neutrinos.