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A. A. Kozhevnikov

Publications and source records attributed to A. A. Kozhevnikov.

At least 37 records · Page 2Linked to original sources
arXiv2005

Branching ratios of the decays of psi(3770) and Upsilon(10580) into light hadrons

Taking into account the new data on the full width of D^{\ast\pm}(2010) and the mass difference of the charged and neutral beauty mesons B^\pm, B^0,\bar B^0, the branching ratios of the decays psi(3770), Upsilon(10580) to pi^+pi^-, K bar K, rho(omega)pi, rho(omega)eta, rho(omega)eta^prime, K^ast bar K+ c.c, rho^+ rho^-, and K^ast bar K^ast are re-evaluated in the model in which the Okubo-Zweig-Iizuka rule is violated due to the real intermediate state D\bar D in case of psi(3770) and B\bar B in case of Upsilon(10580). The inclusive annihilation of psi(3770) and Upsilon(10580) into light hadrons is discussed.

hep-ph↗
arXiv2005

Role of a_1(1260) resonance in multipion decays of light vector mesons

The contribution of the a_1(1260) meson to the amplitudes of the decays rho(770) to 4 pi, omega(782) to 5 pi, and phi(1020) to 5 pi is analyzed in the chiral model of pseudoscalar, vector, and axial vector mesons based on the generalized hidden local symmetry added with the anomalous terms. The analysis shows that inclusion of a_1 meson in the intermediate states results in enhancement of the branching ratios of the above decays by the factor ranging from 1.3 to 1.9 depending on the mass of a_1 meson ranging from 1.23 GeV to m_{a_1}=m_rho sqrt{2}=1.09 GeV, the greater factor standing in case of lower mass of the a_1.

hep-ph↗
arXiv2003

The decays omega(782), phi(1020) to 5 pi in the hidden local symmetry approach

The decays omega -> 2pi^+ 2pi^- pi^0 and omega -> pi^+ pi^- 3pi^0 are reconsidered in the hidden local symmetry approach (HLS) added with the anomalous terms. The decay amplitudes are analyzed in detail, paying the special attention to the Adler condition of vanishing the whole amplitude at vanishing momentum of any final pion. Combining the Okubo-Zweig-Iizuka (OZI) rule applied to the five pion final state, with the Adler condition, we calculate also the phi -> 2pi^+ 2pi^-pi^0 and phi -> pi^+ pi^- 3pi^0 decay amplitudes. The partial widths of the above decays are evaluated, and the excitation curves in e^+e^- annihilation are obtained, assuming reasonable particular relations among the parameters characterizing the anomalous terms of the HLS Lagrangian. The evaluated branching ratios B(phi -> pi^+ pi^- 3pi^0)~2x10^{-7} and B(phi -> 2pi^+ 2pi^- pi^0)~7x10^{-7} are such that with the luminosity L=500 pb^{-1} attained at DAFNE phi factory, one may already possess about 1685 events of the decays phi -> 5pi.

hep-ph↗
arXiv2002

Phase Sensitive Shot Noise in an Andreev Interferometer

We investigate nonequilibrium noise in a diffusive Andreev interferometer, in which currents emerging from two Normal metal/Superconductor (N-S) interfaces can interfere. We observe a modulation of the shot noise when the phase difference between the two N-S interfaces is varied by a magnetic flux. This is the signature of phase-sensitive fluctuations in the normal metal. The effective charge inferred from the shot noise measurement is close to q_eff=2e but shows phase-dependent deviations from 2e at finite energy, which we interprete as due to pair correlations. Experimental data are in good agreement with theoretical predictions based on an extended Keldysh Green's function approach.

cond-mat.mes-hall↗
arXiv2001

Measuring the finite width and unitarity corrections to the phi-omega mixing amplitude

It is shown that the phase of phi-omega interference in the reaction e^+e^- -->pi^+ pi^- pi^0 at energies close to the phi(1020) peak can be calculated in a way that is practically independent of the model of phi-omega mixing. The magnitude of the presently measured interference phase, still of poor accuracy, is in agreement with the predictions based on extending the omega(782) resonance tail from the peak position to the phi mass upon assuming the omega -->rho pi -->3pi model. The calculated omega width at the phi mass is about 200 MeV.

hep-ph↗
arXiv2000

Explaining critical angular velocities of the vortex formation in a stirred Bose-Einstein condensate

The problem of explanation of the critical angular velocity $Ω_c$ when the formation of a vortex in the stirred Bose-Einstein condensate becomes energetically possible, is considered in the framework of the variational approach. The origin of smallness of the calculated $Ω_c$ in comparison with the measured values which takes place for pure quantum state with the unit angular momentum per condensed particle, is uncovered. The agreement with the measured $Ω_c$ is achieved upon admitting a small admixture of the zero angular momentum state in the wave function of the one-vortex quantum state prepared after stirring. The portion of this admixture amounts to 10 - 13 % of the total condensed atoms. Possible test of this hypothesis is proposed.

cond-mat↗
arXiv2000

Many pion decays of rho(770) and omega(782) mesons in chiral theory

The decays rho(770) to 4 pi and omega(782) to 5pi are considered in detail in the approach based on the Weinberg Lagrangian obtained upon the nonlinear realization of chiral symmetry, added with the term induced by the anomalous Lagrangian of Wess and Zumino. The partial widths and excitation curves of the decays rho^0 to 2 pi^+ 2 pi^-, pi^+ pi^- 2 pi^0, rho^{+-} to 2 pi^{+-} pi^{-+} pi^0, rho^(+-} to pi^(+-} 3 pi^0 are evaluated for e^+e^- annihilation, photoproduction and tau lepton decays. The results of calculations are compared with the recent CMD-2 data on the decay rho^0 to 2 pi^+ 2 pi^- observed in e^+e^- annihilation. The omega to 5 pi decay widths and excitation curves in e^+e^- annihilation are obtained. The angular distributions for various combinations of the final pions in the decays rho to 4 pi and omega to 5 pi are written. The perspectives of the experimental study of the above decays in e^+e^- annihilation, tau lepton decays and photoproduction are discussed.

hep-ph↗
arXiv2000

On the masses, branching ratios, and full widths of heavy rho', rho'' and omega', omega'' resonances

Based on the previous and recent fits of multiple data on the reactions of e^+e^- annihilation, tau lepton decay, and the reaction K^-p -> pi^+pi^- Lambda, the magnitude of the branching ratios and total widths of the isovector rho', rho'', and the isoscalar omega', omega'' resonances are calculated. Some topics on the spectroscopy of the rho(1450) and omega(1420) states are discussed.

hep-ph↗
arXiv2000

The decay omega(782) -> 5 pi in chiral theory

The arguments are put forward that the many pion decays omega ->2 pi^+ 2 pi^- pi^0 and pi^+ pi^- 3 pi^0 provide an ideal test site for testing the predictions of chiral models of the vector meson decays into many pions. Using the approach based on the Weinberg Lagrangian or, in a new language, the Lagrangian of hidden local symmetry added with the term induced by the anomalous Lagrangian of Wess and Zumino, the partial widths of these decays are evaluated, and their excitation curves in e^+e^- annihilation are obtained. The discussed are the perspectives of the experimental study of the decays omega -> 5 pi in e^+e^- annihilation and photoproduction.

hep-ph↗
arXiv1999

Chiral dynamics of many pion systems: the rho to 4 pi and omega to 5 pi decays

Based on the Weinberg lagrangian or, in a new language, the lagrangian of hidden local symmetry added with the term induced by the anomalous lagrangian of Wess and Zumino, the dynamics of the decays rho to 4 pi and omega to 5 pi is considered. The excitation curves of rho resonance in its decay to 4 pi are obtained for the first time. The comparison with recent CMD-2 data is given. The partial widths of the decays omega to 2 pi^+ 2 pi^- pi^0 and omega to pi^+ pi^-3 pi^0 which can be measured on colliders with luminosity 10^{33}{cm }^{-2}{s}^{-1} are evaluated for the first time.

hep-ph↗
arXiv1999

Chiral dynamics of many-pion systems

Based on the Weinberg lagrangian or, in a new language, the lagrangian of hidden local symmetry added with the term induced by the anomalous lagrangian of Wess and Zumino, the dynamics of the decays rho to 4 pi and omega to 5 pi is considered. The excitation curves of rho resonance in its decay to 4 pi are obtained for the first time. The comparison with recent CMD-2 data is given. The partial widths of the decays omega to 2 pi^+ 2 pi^- pi^0 and omega to pi^+ pi^- 3 pi^0 which can be measured on colliders with luminosity 10^{33}{cm }^{-2}{s}^{-1} are evaluated for the first time.

hep-ph↗
arXiv1999

Gauge string in the fermion asymmetric matter

Two new effects of interaction of the gauge string with a homogeneous density of fermions are considered in a gauge model with an anomalous coupling of vector fields with fermions. First, the presence of an induced nonzero magnetic-like helicity on the straight string is demonstrated. Second, it is shown that the equation of motion of the string is modified by a nonlinear term that can be decomposed into the correction to the string tension and an additional force perpendicular to the tangent and normal vectors of the string. Static configurations are found and their stability is studied.

hep-ph↗
arXiv1999

Gauge vortex dynamics at finite mass of bosonic fields

The simple derivation of the string equation of motion adopted in the nonrelativistic case is presented, paying the special attention to the effects of finite masses of bosonic fields of an Abelian Higgs model. The role of the finite mass effects in the evaluation of various topological characteristics of the closed strings is discussed. The rate of the dissipationless helicity change is calculated. It is demonstrated how the conservation of the sum of the twisting and writhing numbers of the string is recovered despite the changing helicity.

hep-ph↗
arXiv1999

Exclusive hadron production in e^+e^- collisions up to the J/psi energy

The predictions are presented for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The comparison with existing data on the decays of J/psi and psi(2S) mesons into such hadrons shows that some new resonance structures may be present in the mass range between 2 GeV and the J/psi mass. Searching them may help in a better understanding of the mass spectrum in quark models, and in revealing the details of the three-gluon mechanism of the OZI rule breaking.

hep-ph↗
arXiv1998

Electromagnetic form factors in the J/ψmass region: The case in favor of additional resonances

Using the results of our recent analysis of e^+e^- annihilation, we plot the curves for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The comparison with existing data on the decays of J/ψinto such hadrons shows that some new resonance structures may be present in the mass range between 2 GeVand the J/ψmass. Searching them may help in a better understanding of the mass spectrum in both the simple and a more sophisticated quark models, and in revealing the details of the three-gluon mechanism of the OZI rule breaking in K\bar K channel.

hep-ph↗
arXiv1998

Isoscalar resonances with J^{PC}=1^{--} in e^+e^-annihilation

The analysis of the vector isoscalar excitations in the energy range between 1 and 2 GeV of the $e^+e^-$ annihilation is presented for the final states $π^+π^-π^0$, $ωπ^+π^-$, $K^+K^-$, $K^0_SK^\pmπ^\mp$ and $K^{\ast0}K^-π^++ c.c$. The effects of both the resonance mixing and the successive opening of multiparticle channels, with the energy dependent partial widths, are taken into account. The work extends our previous analysis hep-ph/9609216 of the vector isovector excitations and is aimed to compare the existing data with the predictions of the $q\bar q$ model. It is shown that this hypothesis does not contradict the data.

hep-ph↗
arXiv1997

Decay of Z-string due to the fermion emission

The question of classical topological stability of the gauge vortex defects is reanalyzed upon taking into account the quantum perturbative effects. The purely Abelian Higgs string remains stable while the coupling of the effectively Abelian Z-string (with the fixed zero upper component of the scalar doublet) to the fermions of the minimal standard model is shown to result in its decay, via the fermionic pair emission. The decay rate is scaled as $10^{-1}$ of the decay rate of $Z^0$ boson. The influence of the surrounding charge-asymmetric fermionic matter is considered, demonstrating the dependence of the decay rate on the contour shape and its suppression at sufficiently large charge asymmetry.

hep-ph↗