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Using the approach based on Bogoliubov compensation principle is applied to the calculation of a contribution to the muon g − 2. Using the previous results on spontaneous generation of the effective anomalous three-boson interaction we calculate the contribution, which proves to agree with the well-known discrepancy. The calculated quantity contains no adjusting parameters but the experimental values for the muon and the W -boson masses. The result can be considered as a confirmation of the approach. [ABSTRACT FROM AUTHOR]

We consider the possibility of the spontaneous appearance of an effective coupling in the quantum gravity framework. We discuss a variant of the behavior of the running coupling constant of gravity caused by an effective intergraviton coupling, which entails a qualitative description of the hypotheses on the existence of dark matter and dark energy. [ABSTRACT FROM AUTHOR]

We apply the Bogoliubov compensation principle to the gauge electroweak interaction. We demonstrate a spontaneous appearance of an anomalous gauge-invariant effective three-boson interaction. The nontrivial solution of the compensation equations uniquely determines the form factor of the anomalous interaction and the parameters of the theory including the value of the gauge electroweak coupling in satisfactory agreement with its experimental value. [ABSTRACT FROM AUTHOR]

The recently reported effect of long-range near-side angular correlations at LHC occurs for large multiplicities of particles with 1 GeV< p<3 GeV. To understand the effect several possibilities have been discussed. In the letter we propose a simple qualitative mechanism which corresponds to gluon bremsstrahlung of quarks moving with acceleration defined by the string tension. The smallness of azimuthal angle difference Δ φ along with large Δ η at large multiplicities in this interval of p are natural in this mechanism. The mechanism predicts also bremsstrahlung photons with mean values of p≈2.9 and 0.72 GeV. [ABSTRACT FROM AUTHOR]

In previous works effective nonlocal SU(2)×SU(2) NJL model was proposed in which all the parameters are expressed through those of the fundamental QCD: current light quark mass m0 and average nonperturbative αs. The results for scalar and pseudoscalar mesons are in satisfactory correspondence to existing data. In the present work the same model without introduction of any additional parameters is applied for a description of masses and strong decay widths of ρ- and a1-mesons. The results for both scalar and vector sectors agree with data up to accuracy of the model. [ABSTRACT FROM AUTHOR]

We apply Bogolubov approach to QCD with two light quarks to demonstrate a spontaneous generation of an effective interaction, leading to the Nambu–Jona-Lasinio model. The resulting theory contains two parameters: average low-energy value of αs and current light quark mass m0. All other low-energy parameters: the pion decay constant, mass of the π-meson, mass of the σ-meson and its width, the constituent quark mass, and the quark condensate are expressed in terms of the two input parameters in satisfactory correspondence to experimental data and chiral phenomenology. For example, in the approximation being used we have for αs = 0.67 and m0 = 20 MeV: fπ = 93 MeV, mπ = 135 MeV, mσ = 492 MeV, Γσ = 574 MeV, mq = 295 MeV, $\langle\bar q q\rangle = -(222~{\rm MeV})^3$. [ABSTRACT FROM AUTHOR]

Within QCD involving two light quarks, the possibility of a spontaneous generation of effective interaction leading to Nambu-Jona-Lasinio model is studied by using the Bogolyubov quasiaverage approach. The compensation equation for the form factor of this interaction is shown to have a nontrivial solution that leads to a theory involving two parameters: the average value of the low-energy constant α s and a dimensional parameter f π. All of the remaining parameters, including the current and constituent quark masses, the quark condensate, the pion mass, and the sigma-meson mass and width, are expressed in terms of the input parameters in satisfactory agreement with experimental phenomenology. The results obtained here give sufficient grounds to conclude that the proposed approach is applicable in low-energy hadron physics and that it can be used in dealing with other problems. [ABSTRACT FROM AUTHOR]

Under assumption of singular behavior of invariant charge αs(q2) at q2≃0 and of large q2 behavior, corresponding to the perturbation theory up to four loops, a procedure is considered of smooth matching the β-function at a boundary of perturbative and nonperturbative regions. The procedure results in a model for αs for all q2>0 with dimensionless parameters being fixed and dimensional parameters being expressed in terms of only one quantity ΛQCD. The gluon condensate which is defined by the nonperturbative part of the invariant charge is calculated for two variants of "true perturbative" invariant charge, corresponding to freezing option and to analytic one in nonperturbative region. Dimensional parameters are fixed by varying normalization condition $\alpha_s(m^2_\tau)=0.29,0.30,\ldots,0.36$. It is obtained that on the boundary of perturbative region $\alpha_0=\alpha_s(q_0^2)\simeq 0.44$, the procedure results in nonperturbative Coulomb component αCoulomb≃0.25, the nonperturbative region scale q0≃1 GeV, the model parameter σ≃(0.42 GeV)2 which suits as string tension parameter, the gluon condensate appears to be close for two variants considered, K≃(0.33–0.36 GeV)4 (for $\alpha_s(m^2_\tau)=0.33$). [ABSTRACT FROM AUTHOR]

We consider the theory of a massless scalar field ϕ with the gϕ3 coupling in a six-dimensional space. We use Bogoliubov's method of quasiaverages to study the possibility of a breaking of the original scaling symmetry and of the corresponding spontaneous generation of the effective Gϕ4 coupling. We show that the linearized compensation equation for the form factor of this coupling has a nontrivial solution through the third-order approximation. In the same approximation, the Bethe–Salpeter equation for a massless scalar bound state of two fields ϕ also has a solution. Matching the values of the form factor and the scalar field mass m at zero leads to a unique solution that gives a relation between the parameters of the gϕ3 coupling and the parameters G and m. We argue in favor of the stability of the nontrivial solution obtained. [ABSTRACT FROM AUTHOR]

The deviations from the Standard Model in the probability of Z→bb decay and in the forward–backward asymmetry in the reaction e[sup +]e[sup -]→bb are studied in the framework of the model of dynamical electroweak symmetry breaking, the essential feature of which is the existence of a triple anomalous W-boson vertex in a region of momenta restricted by a cutoff Λ. We obtain a set of equations for additional terms in the Wbt vertex and apply its solution to the process Z→bb. We show that it is possible to obtain a consistent description of both deviations, which is quite nontrivial because these effects are not simply correlated. The necessary value of the anomalous W interaction coupling, λ=- 0.22±0.01, is consistent with existing bounds and leads to definite predictions, e.g., for pair W production in e[sup +]e[sup -] collisions at LEP200. © 1997 American Institute of Physics. [ABSTRACT FROM AUTHOR]