abstract

The paper discusses dynamical properties of the Jacobi field, i.e. the field of perturbations, in general, classical field theories. Propositions about the connection between the Jacobi equations and the principle of stationary action in field theories are formulated and then some first integrals of these equations derived. Their comparison with first integrals of the Lagrange equations suggests the necessity of a generalization of the concept of the Jacobi field. Such a generalization leads to an infinite set of fields which defines the relative dynamics of a given field theory. In concluding remarks attention is paid to the possible meaning of the relative dynamics for the quantization of nonlinear field theories, and in particular of general relativity.

abstract

It is shown that free fields on some manifolds larger than the Minkowski space M(M\(\times \)SU(2), M\(\times \)SU(2)\(\times \)SU(2)) can be regarded as fields describing a composite system of two or three point particles.

abstract

The forward photon–proton scattering amplitude has been evaluated for complex energies. The question of the number and locations of zeros of this amplitude is considered.

abstract

This paper continues recent work by Pokorski and the present author on the description of high energy hadron collisions by means of the quark-glue model of hadron structure. It gives a concrete example of joint distribution \(g(x_1,x_2,x_3)\) of the nucleon valence quarks which reproduces the deep inelastic structure functions of both proton and neutron for \(x \gtrsim 0.2\)–0.3 and gives at the same time a realistic leading particle spectrum for non-diffractive pp collisions. Additional contributions to the structure functions are discussed, in particular, the physical reasons for their concentration at small \(x\). The extension of the quark-glue mode] to hadron-nucleus collisions is briefly discussed.

abstract

The cross sections for the (n,2n), (n,p) and (n,\(\alpha \)) reactions on the target nuclei \(^{85}\)Rb and \(^{87}\)Rb were measured by the activation technique in the neutron energy range from 13 MeV to 18 MeV. The experimental excitation curves are interpreted in terms of the compound nucleus and the precompound emission models.

abstract

The reaction (\(\alpha \), 2n\(\gamma \)) on the \(^{89}\)Y target was used to populate excited states in \(^{91}\)Nb. The gamma-ray transitions belonging to this nucleus were identified by studying excitation functions and gamma–gamma coincidences. Angular distributions, life-time measurements and coincidences with charged particles were also performed. The shell model analysis is used to interpret the observed levels. Nearly all levels belonging to the (g\(_{9/2})^3\) and p\(_{1/2}\)(g\(_{9/2})^2\) proton configurations were found. Matrix elements of the effective proton–proton interactions were determined from the positions of the negative-parity states. These were used to calculate the energy differences of the positive parity states. Satisfactory agreement between the theoretical and experimental values was obtained.

abstract

The angular distribution of neutrons from the \(^{16}\)O(t,n)\(^{18}\)F reaction is measured for five triton energies in the energy range from 1.1 to 1.7 MeV. The reaction in this energy interval was found to go mainly through the compound nucleus. Total cross sections of the reaction were determined.

abstract

Angular correlations coefficients are calculated for the nuclear cascade process \(j_0\)(mezoatom) \({\mu ^- \atop \longrightarrow }\ j_1 {\gamma \atop \longrightarrow }\ j_2\). When introducing explicitly a photon polarization density matrix, a new quantity is distinguished. It is the imaginary part of the muon capture partial amplitudes, providing another check of the \(T\)-invariance in the \(\mu \)-capture. The new quantity could be measured only by means of the linear polarization of the emitted \(\gamma \)-quanta.

abstract

Coulomb displacement energy in the isobaric analog pairs Ti–V is considered. The theoretical calculations of Coulomb displacement energy for \(^{49}\)Ca–\(^{49}\)Sc, \(^{49}\)Ti–\(^{49}\)V, \(^{51}\)Ti–\(^{51}\)W are performed and the results are discussed and compared with the experimental data.

abstract

Referring to the topological expansion for strong interactions, we consider as a mechanism for multiproduction the emission of central clusters identified with hadronic states lying on the pomeron trajectory.