Radiative decays of the Z boson

We calculate the Stokes parameters of the photons produced in the decays of neutral vector bosons Z, Z 1+¯1+ and Z q+¯q+, wherel=e, , or , and q is a quark. In the decays of unpolarized Z bosons (with the production of unpolarized leptons or quarks) the nonzero Stokes parameters for ₂ (circularly polarized photons) and ₃ (linearly polarized photons). The magnitude of ₃ does not depend on the parameters of the netural weak current of the leptons and the quarks (if their mass is neglected). The anomalous magnetic moment of the Z boson is studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 38–43, February, 1986.     

Joint creation of Z-boson and photons by colliding e+e− beams

Density matrix elements for a Z-boson created in the reaction e⁺+e^–Z+, are computed. Two reference frames are used in computations: the center-of-mass frame of the reaction e⁺+e^–Z+ with polarization states of the Z-boson specified by the polarization 4-vector with definite helicities, and the rest frame of the Z-boson. In both cases P-odd phenomena should stipulate particular combinations of the density matrix elements. The energy behavior of the total cross-section of the process e⁺+e^–Z+ is studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 3–6, September, 1982.     

Branching Fraction Measurements of the SM Higgs with a Mass of 160 GeV at Future Linear e + e − Colliders

Assuming an integrated luminosity of 500 fb^–1 and a center-of-mass energy of 350 GeV, we examine the prospects for measuring branching fractions of a Standard Model-like Higgs boson with a mass of 160 GeV at the future linear e⁺e^–collider TESLA when the Higgs boson is produced via the Higgsstrahlung mechanism, e⁺e^– HZ. The Higgs boson mass chosen close to the W pair threshold covers a mass regime with complicated background structures. We study in detail including some detector responds the precisions achievable for the branching fractions of the Higgs boson into WW^(*), ZZ^* and , whereas the measurement of BF(H ) remains a great challenge. Expectations for the total Higgs width are discussed using either the BF(Z ZZ^*) measurement of this study and the expected error for the inclusive Higgsstrahlung cross section or in addition the precise cross section expected for the weak boson fusion process, e⁺e^– v H, or W,Z-universality.     

Energy spectrum and angular distribution of muons from the decay of heavy leptons produced in colliding electron-positron beams

On the basis of an arbitrary (V, A) structure of the neutral weak ¯ee and LL currents (L=^–, M⁰) a study is made of the processes of production in colliding electron-positron beams of pairs of heavy leptons with subsequent decays in accordance with the schemes e⁺e^––(µ^–v_µv) + ⁺( anything) and e⁺e^–M⁰(µ^–e⁺v_e) + M⁰( anything). The energy spectrum and asymmetry of the distribution of the produced muons are investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 66–70, February, 1981.     

Gluon and quark jets in deep-inelastic scattering of electrons by nucleons

The paper considers the formation of gluon and quark jets in the inelastic scattering of electrons by nucleons with large momentum transfers. It is assumed that these jets are created by the processes e^–+qe^–+q+g and e^–+ g e^–+q+q, where q is a quark and g is a gluon. The angular distributions of gluon and quark jets are calculated in the lowest order in the quark-gluon coupling constant. It is shown that after integration the processes e^–+qe^–+q+g and e^–+g e^–+q+¯q lead to violation of the scaling invariance of deep-inelastic scattering of electrons by nucleons.Translated from Izvestiya Vysshkikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 68–73, September, 1981.     

Effect of violating t-invariance of the electromagnetic interaction of hadrons in the processes n + p → d + γ and n + → d + e++e−

T-odd correlations that are possible in the processes n + p d + and n + p d + e⁺ + e^e- and that arise due to the capture of thermal neutrons are determined in terms of threshold amplitudes (for the process n + p d + @#@) or electromagnetic inelastic form factors (for the process n + p d+ e⁺ + e^e§-). The mechanism of these reactions is not given in concrete form, but those general properties of the electromagnetic hadronic current are used that are preserved with three-dimensional reflections.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 8–13, October, 1986.     

Rate equations in the hopping transport

The usual kinetic equations for the site occupation probabilities in an external field are solved exactly in a simple one-dimensional periodic model with two kinds of atoms using a) free boundary conditions and order of limitsN, 0 needed for a proper treatment of the dc conductivity here b) boundary conditions with metallic contacts and order of limitsN, 0 and c) the same boundary conditions but reversed order of limiting processes 0,N typical of e.g. numerical and percolation treatments. (N and are the number of sites and frequency.) It is demonstrated that though the bulk dc conductivity is the same in all three cases, local bulk properties of the material are strongly dependent on the régime used. The role of the order of all three limiting processes 0,N+ andn+ (N–n+) for local shifts of the chemical potential _n in the dc limit is examined (n is the number of the relevant site calculated from a boundary of the chain). It is shown especially that the rate equation treatment (régime a) on the one hand and numerical or percolation treatments (régime c) on the other hand never yield the same bulk values of _r.     

Some weak processes in electron-proton collisions

Polarization effects are investigated for processes of single production of strange particles in electron-proton collisions e^±+p ⁺+e^±. Special attention is paid to effects associated with possible application for investigation of similar processes of polarized electron beams and polarized nucleon targets. We point out the important role of the study of polarization effects for determination of the matrix element of processes of the type e^±+p ⁺+e^±.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 78–82, September, 1990.     

π0 → γγ in the Spinor Strong Interaction Theory

An expression for the decay rate (⁰ ) has been derived in the frameworkof the spinor strong interaction theory, a first-principles strong interaction theoryproposed some years ago as an alternative to low-energy QCD. The startingpoint is the SO(3) gauge-invariant action for two quark mesons which has beensuccessful in accounting for confinement, ^{+ +} , e⁺, and ⁰ e⁺, nonexistenceof the Higgs boson, and other low-energy mesonic phenomena. The quasi-four-quarkmeson equations developed for the decay of a vector meson into twopseudoscalar mesons V PP has been taken over here to apply to P(⁰) VV(^{+ –}) (plus ⁺ and ^– which annihilate each other). This mechanismin principle agrees with that of the assumption of vector meson dominance inthe literature. It, together with the effect of form factors, arises naturally in theformalism and need not be assumed. Equations for the perturbed vector mesonwave functions cannot be simply solved and an assumption has been made toobtain an estimate of their magnitude. Together with a constant associated withthe strong coupling obtained earlier from V() PP(K⁺K^–), the estimated decayrate is 19.2 eV, in order-of-magnitude agreement with data (7.74 eV).     

π-Meson absorption by three-particle nuclei

The reactions ⁺ +³He 3p and ^– +³H 3n are considered with both two- and three-nucleon pion-absorption taken into account. The pion-absorption with all nucleons of the nucleus involved and the interference of the two absorption mechanisms are shown to be of the same importance as a pure two-particle absorption in nuclei. The latter cannot be considered dominating as it used to be.     

Dynamical chaos in the highly excited states of a quantum Daffing oscillator in an external harmonic field

The energy spectrum of the highly excited states of a quantum Daffing oscillator is considered. It is shown that the energy levels satisfy E_n>E_n+1 and E_n -F²/8², when n , where F² and are the intensity and frequency of the external field. It is suggested that this property of the spectrum is the quantum manifestation of a stochastic attractor in the classical nonlinear limit. This property also takes place for large F².Omsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 90–94, March. 1993.     

Time-asymptotic boson states from infinite mean field quantum systems coupled to the boson gas

By means of cocycle techniques in a recent paper, the global dynamics of mean field-boson couplings has been studied. Here, by restricting to the bosonic system the infinite time limit (t ) for very general initial states, one obtains time-asymptotic states on the bosonicC ^*-Weyl algebra, in which one partially rediscovers the collective ordering of the infinite mean field lattice.     

Hadronic vacuum polarization contribution to the Lamb shift in muonic hydrogen

We report on the accuracy of the measurement of the total cross section of the process e⁺e^– ZH and of the Higgs boson mass that would be achieved in a linear collider operating at a centre-of-mass energy of 350 GeV, assuming an integrated luminosity of 500 fb^–1. For that we have exploited the recoil mass off the Z using its leptonic decays into electron and muon pairs. The Higgs mass is determined with 150 MeV accuracy, the recoil mass resolution is about 1.5 GeV and the cross section is obtained with a statistical error of 3%.     

Appearance of P-odd nuclear forces in photoproduction of pions on6Li

P-odd effects in the photoproduction of pions on⁶Li nuclei, +⁶Li ⁺ +⁶He, are studied. Collisions of linearly and circularly polarized photons with a polarized nuclear target are studied, and in addition both vectorial and tensorial polarization are taken into account. It is shown that in the general case P-odd effects in +⁶Li ⁺ +⁶He are characterized by 18 real structure functions, which determine different P-odd asymmetries in the angular distribution of the pions. The structure functions in their turn depend on different products of three p-even and three p-odd amplitudes of the process +⁶Li ⁺ +⁶He. The P-odd effects at the threshold of the reaction +⁶Li ⁺+⁶He are analyzed. Using available experimental data on the behavior of the cross section of the reaction +⁶Li ⁺ +⁶He at threshold, the ⁶Li⁶He strong-interaction constant is evaluated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 78–82 July 1985.     

Relativistic Hypernuclei: Old Problems and New Prospects

The first experiments with relativistic hypernuclei (Bowen; Khorozov and Lukstins) were done many years ago. They demonstrated not only that such extremely difficult experiments are manageable but also their great advantage, a possibility of observing and studying independently the production and weak decay of hypernuclei: the points of the production and decay of relativistic hypernuclei are separated by tens of centimeters instead of some microns in classical experiments. At the same time these first experiments revealed a huge problem with selection of the proper trigger.Recently we proposed to explore a unique feature of the ⁹Be nucleus: after removing a neutron from its ground state several groups of alpha-particles appear from different excited states of a residual nucleus ⁸Be. Detection of the correlated pair of -particles produced in a vacuum volume at a distance of some 40 cm from target is an unambiguous signal of nonmesonic decay of hypernucleus ¹⁰ Be(++n+n) or ¹⁰ Be(++n+p). In this particular case it is possible to take exclusive decay rates (on different excited states of ⁸Be^*). This open a way for a phenomenological analysis of matrix elements of the four-baryon weak interaction.The experiment is approved for new accelerator Nuclotron at JINR, Dubna.     

Resonance interaction of antineutrinos with electrons

Expressions are given for the cross sections of the processes v_ee v and v_ee v _e ^' e' from the viewpoint of the hypothesis of weak interactions via intermediary vector mesons taking separate account of the polarizations of the electron target and the muon (electron) emission. An analysis is given of the cross sections of processes which are admissible according to both the two- and four-component theories of the neutrino. The degree of longitudinal polarization of meson emission is also determined for the interaction of incident antineutrinos (neutrinos) with a polarized target in the processes ve v, ve⁺ v⁺.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 6, pp. 48–53, June, 1971.The author is grateful to B. K. Kerimov for his useful advice which stimulated the appearance of this work and also to Yu. M. Kasumov for his constant assistance with the work.     

Bremsstrahlung of soft photons in the reaction p + p → π+ + d + γ

The limit theorem of Low is used to construct the amplitude of the soft bremsstrahlung accompanying the reaction p + p ⁺ + d. The obtained amplitude is expressed in terms of the amplitudes of the nonradiative process.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 29–32, December, 1970.     

Scalar particle with polarizability in a uniform external magnetic field

The model of a scalar structured particle is considered, which possesses polarizability in an external electromagnetic field. The expression for the 4-dimensional current density is found. The exact solution of the equations describing a scalar particle with polarizability in a uniform external magnetic field is obtained. Up to the terms of order O(H²), the energy spectrum can be formally obtained by the substitution of the particle mass in the expression for a pointlike scalar particle: mm–H²/2, where is the magnetic polarizability of the particle. It is shown that the rms radius of a trajectory can be obtained by the substitution of the charge in the well-known formula for a structureless scalar particle: ee(1{-H²/m)^1/2 (where is the electric polarizability).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 91–94, January, 1991.I thank A. I. L'vov for discussions.     

The\bar pp \to e^ + e^ - reaction at rest and the hierarchy of the annihilation ranges

A new procedure is devised to evaluate the proton form-factor at the ¯pp threshold from experimental data on ¯ppe ⁺ e ^– annihilation at rest. Comparison of the ¯ppe ⁺ e ^– and¯pp ^+– processes reveals that annihilation ranges for various channels are ranked in line with quark dynamics.This work has been funded in part by the German Federal Minister for Research and Technology (BMFT) under the contract number 06HD756