abstract

Adding the cosmological term, which is assumed to be variable, in Brans–Dicke theory we have discussed different cylindrically symmetric models which are of Petrov type I or Petrov type D. The physical and geometrical properties of these models have been discussed. Finally these models have been transformed to the original form (1961) of Brans–Dicke theory (including a variable cosmological term).

abstract

Equations of state for an irrotational perfect fluid are investigated. It is shown that the equations of state in the form a) \(\varrho =\) const, \(P\not =\) const, b) \(P =\) const, \(\varrho _{,k} = \varrho _{,n}u^nu_k \not = 0\), c) \(P_{,k} = P_{,n}u^nu_k\), \(\varrho _{,k}=\varrho _{,n}u^nu_k\), d) \(\varrho _{,k} = \alpha P_{,k}\), \(\varrho _{,n}u^n=P_{,n}u^n=0\) do not contradict the Einstein field equations. Finally we present the physically realistic equations of state.

abstract

It is shown that Cabibbo-like mixing is related to a non-diagonal fermion mass which may be generated by the Higgs mechanism involving scalars of higher generations. Then a spontaneously broken symmetry group is given by SU(2) \(\times \) U(1) \(\times \) U\(^{\prime }\)(l), the factor U\(^{\prime }\)(l) being generated by the properly defined particle-generation number.

abstract

The background field approach to calculations in gauge field theories is presented. Conventional functional techniques are reviewed and the background field method is introduced. Feynman rules and renormalization are discussed and, as an example, the Yang–Mills \(\beta \) function is computed.

abstract

The dependence of experimental cross sections of 30 keV neutron radiation capture upon a target-nucleus neutron number, neutron binding energy and level density parameters are analyzed for a wide number of nuclei. On the basis of regularities observed, additional criteria appear of estimating experimental data on averaged cross sections, level density as well as a possibility of more valid prediction of averaged cross sections for other nuclei, for example, for radioactive ones.

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Energy levels of the \(^{147}\)Nd nucleus have been studied by means of the \(^{146}\)Nd (d,p) \(^{147}\)Nd and \(^{148}\)Nd (d,t) \(^{147}\)Nd reactions at a bombarding energy of 12.1 MeV. The reaction products were observed using a magnetic spectrograph and photographic plate recording. The spectroscopic factors for the observed levels were obtained from DWBA calculations.

abstract

The method of phase-variable equations has been used for the bound-state problem of confinement potentials. An equation yielding the bound-state spectrum for the confinement potential has been obtained.

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Spin and isospin stability of dense neutron and nuclear matter with hard core interaction of radius c is investigated with the Iwamoto–Yamada–Jastrow method. Different correlation functions for two nucleons with identical and nonidentical third components of spin–isospin are used. Neutron matter shows spin stability. Onset of spin and isospin instability of nuclear matter is predicted at \(k_Fc \cong 1.1\).

abstract

Excited states in \(^{151}\)Gd have been studied through the (e.c.\(+ \beta ^+\))-decay of \(^{151}\)Tb (16.4 h). The activity was produced through spallation of Ta with 660 MeV protons at JINR and was isolated using chemical and ion-separation techniques. The gamma-ray and electron spectra have been investigated with the help of spectrometers with Ge(Li)- and Si(Li)-detectors. The e-gamma-coincidence spectra were studied by means of a setup based on toroidal beta-spectrometer and spectrometer with Ge(Li)-detector, from conversion electron lines K108.1, K180.2, K192.1, K251.9, K287.2 and K426.6. The decay scheme of \(^{151}\)Tb \(\to ^{151}\)Gd is proposed and discussed.

abstract

The prompt emission of fast nucleons resulting from the Fermi motion of nucleons in nuclei is investigated in Time-Dependent Hartree-Fock theory. The identification and demonstration of the fast nucleons (Fermi jet) is facilitated by plotting the Wigner function in phase-space. The calculations are made in one-dimensional slab-geometry. The number of nucleons in the jet varies with beam energy and with the target-projectile asymmetry. A larger asymmetry (smaller projectile) gives more nucleons. A beam of \(E_{\rm lab}/A =\) 24 MeV gives a maximum number.

abstract

Perturbation theory of the radial distribution function is described by Goldstone diagrams. Our selection of diagrams is guided by Brueckner theory. Thus two-hole line particle–particle ladder diagrams are selected with kinetic energy propagators in a low density approximation. In another selection of diagrams the hole lines are dressed by bubble–insertions in a low-order Brueckner approximation. The normalization of the radial distribution function is discussed. Calculations are presented for nuclear matter with several simplified interactions and for liquid-\(^3\)He with the Lennard–Jones 6–12 potential.

abstract

A recently published work on \(^{237}\)Np(e,f) is commented; inconsistencies regarding data analysis and errors in data interpretation are shown.

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In this note we would like to answer the critical comment by J.D.T. Arruda-Neto and S.B. Herdade Acta Phys. Pol. B13, 157 (1982) (preceding paper) concerning our paper Acta Phys. Pol. B11, 691 (1980).