Regular Series


Vol. 6 (1975), No. 9 – 10, pp. 657 – 781


On the Connection Between Einstein Surface Equations, Raychaudhuri Equation and the Intrinsic Geometry of Null Hypersurfaces

abstract

If teleparallelism is chosen as an affine connection on a null hypersurface \(\stackrel {*}{V}_3\), then expansion \(\theta \) and distortion \(|\sigma |\) may be represented on it in terms of intrinsic geometry of the \(\stackrel {*}V_3\). The Einstein surface equations together with the Raychaudhuri equation for \(\theta \) yield an equation which restricts the intrinsic geometry of that null hypersurface.


The Gauge \(A\)-Field and the Strong Gravity

abstract

The system of the interacting gravitational field and the gauge \(A\)-field, introduced by the authors earlier, is considered in the static, spherically symmetric case. In the asymptotical approximation it is shown that the gauge \(A\)-field behaves as a short-range one with some effective mass, and that the gravitational potential together with the usual long-range term has also the short-range term, typical for the strong gravity.


Connection of the Papapetrou Pseudotensor and the Bel–Robinson Superenergy Tensor

abstract

The expansion of the Papapetrou pseudotensor in the Riemann normal coordinates is obtained in the zeroth, first, and second orders in the coordinates. Pure gravitational terms appear only in the second order and the corresponding coefficient of the expansion is a tensor of the fourth rank. Being symmetrized, this tensor exactly coincides with the Bel–Robinson superenergy tensor which can be hence interpreted as the relative energy-momentum density of the gravitational field.


Muons Produced by Atmospheric Neutrinos from the View-Point of the Photon Neutrino Weak Coupling Theory

abstract

The experimental rate of muons produced deep underground by neutrinos and the atmospheric-neutrino spectrum as determined from cosmic ray muon data has been analysed on the basis of the photon-neutrino weak coupling theory. It is shown that theory of weak interactions based on the photon-neutrino weak coupling and dynamical origin of charge, which predicts that the cross section falls off with energy in the high energy region beyond the threshold energy for large mass resonances, is not in contradiction with the observed rate of muons produced by atmospheric neutrinos.


Dependence of Slope on Mass of the Diffractively Produced \(K^+\pi ^+\pi ^-\) System in the Reaction \(K^+{\rm p} \to K^+\pi ^+\pi ^-\)p at 4.97 GeV/\(c\)

abstract

The method of data analysis proposed by Miettinen and Pirilä which eliminates kinematic reflections in the variation of the slope in momentum transfer distribution, as a function of diffractively produced effective mass, is applied to the reaction \(K^+{\rm p} \to K^+\pi ^+\pi ^-\)p at 4.97 GeV/\(c\). It seems that for this reaction and at this energy, the strong rise of the slope parameter observed for low mass \(K^+\pi ^+\pi ^-\) systems is mostly produced by kinematic effects. There is no proof that a slope-mass correlation must be explicitly present in the invariant matrix element. This does not confirm the results obtained by Miettinen and Pirilä for the reaction pp \(\to \)n\(\pi ^+\)p at 19 GeV/\(c\).


Large Momentum Transfer Corrections to the Glauber Model in Nonrelativistic Eikonal Expansion

abstract

Corrections to the Glauber model for hadron–deuteron scattering in the realm of non-relativistic eikonal expansion are expressed through two-body scattering amplitudes. Numerical calculations including off-shell effects are carried out and the comparison with experimental data is given for elastic \(\pi \)d scattering at 9 GeV/\(c\). Dependence of the relative values of corrections on parameters of input amplitudes is checked. It turns out that this type of corrections does not exceed 22% at the largest momentum transfer measured, \(t\approx -2\)(GeV/\(c)^2\).


Comment on the Shapes of Multiplicity Distributions in pp Collisions

abstract

We discuss the shapes of multiplicity spectra observed in inelastic pp collisions at high energies. It is found that a recent observation, which claims that the negative-particle multiplicity is consistent with a Poisson distribution for high multiplicities, is not valid at the highest Fermilab energies.


Several Ways of Breaking the Colour Symmetry

abstract

We discuss some cases of colour-symmetry breaking and its implications for quark binding by one-gluon-exchange forces. We pay special attention to the case, where colour-isospin and colour-hypercharge subsymmetries are preserved. Then, the \(\omega \)–\({\mit \Phi }\)-like mixing of colour-nonet components 0 and 8 leads to a Zweig-type approximate selection rule for decays of \({\mit \Phi }\)-like meson = \(\overline {q}_{\rm B}q_{\rm B}(q_{\rm B}\) is the “blue” quark) into ordinary mesons (and photons).


Partial Screening of Quark Charge

abstract

The hypothesis of vector–gluon dominance over the coloured part of the photon, if true, implies a phenomenon of partial screening of quark charge, which may be responsible for non-integer values of quark charges as “observed” at present in deep inelastic electron scattering. An average rise of \(R\)-ratio in \(e^-e^+\) annihilation is a necessary condition for our hypothesis. This hypothesis also implies that (besides strong decays) the first-order radiative decays of coloured states into non-coloured states are forbidden if strong interactions are colour symmetric.


New Particles and Breaking the Colour Symmetry

abstract

In the framework of one-gluon-exchange static forces mediated by a colour octet or nonet of vector gluons, we discuss quark binding in coloured-meson states and its connection with breaking the colour symmetry. A possible identification of \(\psi (3.1)\), \(\psi (3.7)\) and the broad bump at 4.1 GeV with some coloured bound states of quarks and antiquarks is pointed out. This identification implies the existence of a second bump in the region of 5 GeV. The general conclusion of the paper is that the colour interpretation of the new particles may be true only if the colour symmetry is badly broken (provided the considered forces are relevant).


Isomeric Cross-Section for the \(^{197}\)Au(p,n) \(^{197,197{\rm m}}\)Hg Reaction in the Energy Interval 6.5–9.5 MeV

abstract

Isomeric ratio in the reaction \(^{197}\)Au(p,n) \(^{197,197{\rm m}}\)Hg in the energy interval 6.5–9.5 MeV, was measured using the activation method. The calculations of \(\sigma _{\rm m}\)/\(\sigma _{\rm g}\) values, expected by statistical model, were performed as well, with the application of the scheme described by Huirenga and Vandenbosch. The best fit to the experimental data was obtained for the level density parameter \(a \simeq 20\), by the fixed spin-cut-off parameter \(\sigma = 4\). On the ground of the same experimental data it was possible to determine the excitation function for (p,n) reaction, which, after normalization, was compared with theoretical one.


Neutron Matter with Recent Nonlocal Separable Nucleon–Nucleon Potentials

abstract

The nonlocal separable nucleon–nucleon potentials, recently applied in the nuclear matter calculations, are used within the frame of the Brueckner theory for the calculation of the equation of state of the pure neutron matter. The results for the potentials, which proved to be most promising in the nuclear matter calculations, coincide with those obtained for the Reid soft core potential in the lowest order Brueckner theory.


On the Brueckner–Gammel Approximation for the Magnetic Susceptibility of Neutron Matter

abstract

The magnetic susceptibility of neutron matter is calculated in the lowest order Brueckner theory for the Reid soft core potential. The rearrangement contributions calculated using the approximation of Brueckner and Gammel are important at the highest densities considered. Contrary to the case of liquid \(^3\)He, the results obtained using Brueckner and Gainmel approximation coincide with those obtained by the other authors within the frame of the Landau theory of Fermi liquids.


Exactly Soluble Model of the Volume Conserving Pairing

abstract

An exactly soluble model for the volume conserving pairing is formulated. It is shown that the non-zero equilibrium energy gap exists only in nuclei having irregularities in spectra near the Fermi surface.


Volume Conserving Pairing and Rotational Bands of \(^{156}\)Dy, \(^{156}\)Er, and \(^{162}\)Er

abstract

Volume-conserving pairing was used to determine the Coriolis-antipairing effect on the rotational bands of \(^{156}\)Dy, \(^{156}\)Er, and \(^{162}\)Er. The results follow the experimental moments of inertia up to the region of the critical spin values quite well. In particular they do not show the too rapid rise of the moment of inertia at low spin values which is difficult to avoid in the “standard pairing” calculation.


Energy Spectra of the \(^{137}\)Ba, \(^{139}\)Ce, \(^{141}\)Nd and \(^{143}\)Sm Nuclei Calculated with the Use of the Particle-Surface Coupling Strength Depending on the Single Neutron–Hole States

abstract

Particle-surface coupling strength matrix elements calculated with Woods-Saxon wave functions are used in the study of the energy spectra of the \(^{137}\)Ba, \(^{139}\)Ce \(^{141}\)Nd and \(^{143}\)Sm nuclei. The comparison with the theory, in which the coupling strength has been treated as a parameter, is made. In both cases the general features of the spectra are similar, although there are some differences, especially in the values of spectroscopic factors. Agreement between calculated nuclear properties and available experimental data is good.


top

ver. 2024.03.17 • we use cookies and MathJax