abstract

Angular correlations of \(\gamma \)-rays in the decay of \(^{125}\)Xe have been measured. The source was obtained by implanting Xe ions in aluminium foil. The results, together with the \(\log ft\) values of electron capture transitions and the transition multipolarities, allow the assignment of spins and parities to the following levels: \(\frac {7^+}{2}\) to 113.6 keV, \(\frac {5^+}{2}\) to 372.1 keV and \(\frac {3^+}{2}\) to 453.8 keV. They also suggest \(\frac {3}{2}\) spin values for the 1090, 1180.5 and 1383 keV levels. The perturbation of the 74.9–113.6 keV correlation is discussed. The spin value for the 113.6 keV level and negative sign for the mixing amplitude of the 113.6 keV transition emerge from the analysis, irrespective of perturbation of the angular correlation. Several new transition in coincidence with 453.8 keV \(\gamma \) quanta were observed.

abstract

An investigation of the \(^{32}\)S(d,p)\(^{33}\)S reaction was made at a deuteron bombarding energy of 12.3 MeV. The energy spectra were measured by magnetic analysis and the obtained angular distributions were compared with the predictions of DWBA, using the deuteron optical model parameters obtained from an analysis of the elastic scattering of deuterons on \(^{32}\)S nuclei. The absolute values of spectroscopic factors, extracted on this basis, indicate a significant contribution of higher configurations in the ground state wave function of the \(^{32}\)S nucleus. There are no. arguments which permit the identification of the observed states of the \(^{33}\)S nucleus as rotational states.

abstract

The assumption of antiquark–quark scattering dominance in the formation of the second diffraction maximum is used to obtain relations between the differential cross-sections in the angular region of the secondary maximum in the framework of the additive quark model with spin. Some of the relations are compared with experimental data.

abstract

The helicity crossing relations between the two-body scattering channels and the three. body decay channel are derived under the assumption that analytic properties of spinor amplitudes allow such a crossing. Each relation contains two or three crossing angles.

abstract

Experiments with unpolarized particles determine only partially the scattering amplitudes. For reactions \(0^-{\frac {1}{2}}^+ \to 0^-{\frac {3}{2}}^+\) and \(0^-{\frac {1}{2}}^+ \to 1^-{\frac {3}{2}}^+\) we give the most general transformation of the amplitudes, which leaves the experimental results unchanged. Implications for the quark model are also discussed.

abstract

A Regge pole model for the reactions \(\pi N \to \pi {\mit \Delta }\), \(\pi N \to \eta {\mit \Delta }\), and \(KN \to K{\mit \Delta }\) is proposed. The description of the decay distributions and differential cross-sections is good. The model contains six free parameters: the intercepts of the \(\varrho \) and \(A_2\) trajectories, a universal slope, the \(\eta \), \(\eta '\) mixing angle, and two coupling constants. The number of free parameters is kept low by the use of the quark model and of the Veneziano formula for the residues. The predictions for the differential cross-sections of the \(\pi ^+p\) processes at 16 GeV/\(c\) are also given.

abstract

An investigation is made of the possibility of extending a previous calculation of the motion of Fermions in a linearized gravitational field to particles of higher spin. The Rarita–Schwinger equations or arbitrary half-integral spin are discussed. It is found that the \(R\)–\(S\) equations for spin \(\gt \frac {3}{2}\) become self-inconsistent in the presence of gravitational field with other than constant Riemann curvature. For spin \(\frac {3}{2}\) the equations are seen to be consistent in the presence of an exterior gravitational field in regions where the sources vanish. The equations for the trajectory of a spin \(\frac {3}{2}\) particle in such a situation are calculated and take the same form as in the spin \(\frac {1}{2}\) case with the appropriate generator of Lorentz transformations appearing in the spin tensor. The deflection of high energy spin \(\frac {3}{2}\) particles passing near a massisve body is computed. Although the corresponding equations for the trajectory of a spin 1 particle can be shown to have the 1 same form as the spin \(\frac {1}{2}\), \(\frac {3}{2}\) cases, it is doubtful whether the result sill hold for spins \(\gt \frac {3}{2}\) except in fields of constant Riemann curvature.

abstract

The result of hermitian symmetry in Einstein’s Unified Field Theory is examined in terms of pseudo-tensor \(U^{\gamma }_{\mu \nu }\) for which the Ricci tensor is hermitian symmetric. Einstein’s expression for \(U^{\gamma }_{\mu \nu }\) is shown not to be unique. It is also shown that there is no Linear expression for the affine connection in term of such a pseudo-tensor which would lead to invariant symmetry conditions.

abstract

The isomeric ratios and excitation functions were measured for the \(^{113}\)In\((a,2n)^{112g,m}\)In and \(^{115}\)In\((n,2n)^{114g,m}\)In reactions in the neutron energy range from 13.1 Mev to 18.2 Mev. The results are compared with the statistical-model predictions. Use was made of modified nuclear level density formulae based on superconductivity theory, which account for the pairing and shell effects.

abstract

This paper presents an analysis of the energy spread of the products of a nuclear reaction in thin targets for a Gaussian — distributed beam of incident particles.