Regular Series


Vol. 4 (1973), No. 3 – 4, pp. 161 – 294


Electromagnetic Decays of \(X^0(960)\) and \(E(1420)\) Mesons

abstract

The electromagnetic decays of the \(X^0\)(960) and \(E\)(1420) mesons are studied. Decays with Dalitz pair production are analysed in detail.


Two-Step Deuteron Stripping on Spherical Nuclei

abstract

The main features of the two-step effects, connected with one-phonon virtual excitations, are analyzed for allowed neutron transfers in the \(^{52}\)Cr\((d,p)^{53}\)Cr reaction. To this end the obvious expression for the cross-sections obtained in the double adiabatic perturbation approach is calculated with the help of an ordinary DWBA-method. A mixture of the two-step effects to the usual one-step cross-section is found to be about 10 per cent, but with increasing incident energy from 10 to 20 MeV the effect increases approximately by a factor of two times.


Analysis of Excitation Functions in Heavy Ion Reactions

abstract

The possibilities of describing the behaviour of excitation functions when applying the statistical models of nuclear reactions incorporating the angular moment of the disintegrating nucleus are studied. The sensitivity of these functions with respect to the choice of the model parameters is analyzed. The competitive effect of the \(\gamma \)-ray emission process and the role of the “critical” angular momentum are discussed. An analysis of the available experimental data provides values of the parameters which allow the yield cross-sections for reactions involving heavy ions to be found with an accuracy of \(k\approx 2\)–3, and the position of the maximum in the excitation function with an accuracy of \({\mit \Delta } E\approx (5\)–10) MeV.


On the Problem of Angular Correlations in Direct Nuclear Reactions

abstract

A formula is obtained for the angular correlation in direct nuclear reactions of the type \(A+\alpha \to B+\beta \to C+\gamma +\beta \). The specific case of the plane-wave approximation is analyzed, and distortions within the framework of the high-energy approximation for the reaction \(^{12}\)C+\(^6\)Li \(\to \) \(^{16}\)O \(+d \to \ ^{12}\)C \(+\alpha +d\) are calculated.


Unified Space-Time for Interaction of Elementary Particles

abstract

In this paper the eight-dimensional Space-Time is utilized for establishing the Elementary Particles Theory free of the ultraviolet infinities. The main results are as follows. A procedure for evaluating the mean values with respect to the directly unobservable parameters is introduced. Although it is formally equivalent to the nonlocality introduced by [1], the theory is still microcausal and the \(S\)-matrix is unitary on the mass shell. In addition, particles are classified in multiplets; the same internal space may be used for both types of particles, leptons and hadrons. It is shown that the Yukawa interaction is deducible from the local gauge transformations in unified Space-Time. The interaction Lagrangians of strong interactions and of leptonic interactions are established.


Exponential Interactions at High Energy

abstract

It is shown that the exponential interaction \(\exp z^2\) leads to Regge-type high-energy elastic scattering amplitudes when summations are carried out in the major coupling constant. A more complicated entire interaction of the same order yields similar results.


Interaction of Relativistic Deuterium and Tritium Nuclei with Photoemulsion Ones

abstract

Inelastic collisions of the deuterons and tritium nuclei with photoemulsion in the energy range up to 30 GeV/nucleon were calculated within the framework of the intranuclear cascade model taking account of the changes in the nucleus-target properties in the process of interaction. In the energy dependence of the slow secondary particle multiplicity at the energy of the order of several GeV a maximum is predicted which is due to the decrease of the intranuclear matter density resulting from the knocking Out of nucleons by the cascade particles. Reliability of the selection of interactions with photoemulsion hydrogen with the aid of the \(n_h \leq 1\) criterion is discussed.


The Effect of the Resonance Production on the Nuclear Reaction Mechanism

abstract

The resonance production processes are taken into account in the framework of the cascade model. It is shown that variation in the nuclear reaction mechanism, occurring at about (3–5) 6eV in the region of medium-weight nuclei, is explained not by the effect of resonances, produced in the internuclear particle collisions, but by the previously considered effect of the local reduction of the nuclear density in proportion to the cascade development. It is pointed out that the contribution of the “many-particle” collisions is unessential in the energy region \(T \lt 30\) GeV.


Excited States \(J^{\pi }=1^+\) in Spherical Nuclei

abstract

Energies, wave functions and Ml electromagnetic transition widths have been calculated for \(^{55}\)Ni, \(^{114,116,118,120,122,124}\)Sn, \(^{138}\)Ba, \(^{140}\)Ce, \(^{142}\)Nd and \(^{208}\)Pb with the use of the Saxon–Woods potential and “realistic” residual forces. Several excited states \(J^{\pi }=1^+\) in the energy region 2.3–12.4 MeV have been obtained for each nucleus. Some of these states are a coherent mixture of configurations generated by spin–orbit interaction and have a large width for M1 electromagnetic transitions.


Scalar-Tensor Theory and Scalar Charge

abstract

For a general class of scalar-tensor theories of gravitation the properties of exact static spherically-symmetric vacuum and electrovac solution are discussed. On the other hand, post-Newtonian perfect fluid metric for this class of theories is found and compared with the exact vacuum solution. This comparison shows that the post-Newtonian approximation employs a special value of the scalar charge-mass ratio. This limitation is removed if a term involving scalar charge density is introduced explicitly into the initial Lagrangian. Observational consequences are discussed.


New Class of the Quantum Markovian Processes and Partial Wave Expansion of Transition Amplitude

abstract

New infinite family of the quantum Markovian processes of diffusional type is found. These processes appear naturally when passing from the Cartesian coordinate system to the polar one in the path integral. They permit us to write closed formulae for partial transition amplitudes and for various physical characteristics of the central potential scattering.


On the Distributions of Total \(\alpha \)-Widths of Neutron Resonances

abstract

Using the Monte-Carlo method, it is shown, that the distributions of total \(\alpha \)-widths may be reasonably described by the \(\chi ^2\) distribution. The number of degrees of freedom for this distribution is given in terms of the transmission coefficients of potential barrier for \(\alpha \)-decay channels. The possibility of spin assignment for some neutron resonances from the total \(\alpha \)-width distribution is pointed out.


On the Bernstein-Salz Conjecture in the Nonlinear Lee Model

abstract

A conjecture of Bernstein and Salz is investigated in the framework of the nonlinear Lee model; an argument is put forward that this conjecture is true.


Purely Internal Geodesic Motion and Resulting Necessary Conditions for Relativistic Spheres

abstract

The study of geodesic motion in internal gravitational fields is of relevance for neutrino emission processes in advanced evolutionary stages of superdense stars. From a general formula for neutrino trajectory in a static field of spherical symmetry certain conditions for the metric are derived in the case when trapped neutrino trajectories arc allowed.


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