Related papers: Mending $\rho\pi\pi$ vertex through the $\pi a_1$ …
We construct the Lagrangian formulation of a micro-structured spinning, dilating and shearing (deformable) test body, moving in arbitrary non-Riemannian backgrounds possessing all geometrical entities of curvature, torsion and…
Phase structure of the four dimensional Nambu -- Jona-Lasinio model has been investigated in two cases: 1) in nonsimply connected space-time of the form $R^3\times S^1$ (space coordinate is compactified and the length of the circle $S^1$ is…
The observation of $\pi_1(1600) \to \pi \rho$ is shown in the flux-tube model to be compatible with this state being a hybrid meson with branching ratio to this channel $\sim 30%$. The $\pi \rho$ widths of other hybrids are related by…
The $d^* \to d \pi \pi$ partial decay width has been calculated in a wave-function model for $d^*$ and $d$. It is found to be smaller than a previous estimate by a factor of 7. A previously proposed dependence on dibaryon sizes is…
A first-order Lagrangian $L^\nabla $ variationally equivalent to the second-order Einstein-Hilbert Lagrangian is introduced. Such a Lagrangian depends on a symmetric linear connection, but the dependence is covariant under diffeomorphisms.…
The necessary and sufficient conditions to construct consistent Lagrangian formulation for irreducible interacting massless higher-spin (HS) fields on $d$-dimensional Minkowski space within approach with incomplete BRST operator and…
We study a chiral quark model of $\pi$, $\sigma$, $\rho$, and $a_1$ mesons in the large-$N_c$ limit. We show that the quadratic $a_1-\pi$ mixing can be set to zero at zero momentum, thus protecting the $g_{\sigma\pi\pi}$ and…
We suggest a parameterization of the matrix element for $\bar{B}^0\to D^{*+}\omega\pi^-$ decay using kinematic variables convenient for experimental analysis. The contributions of intermediate $\omega\pi$- and $D^{**}$-states up to spin 3…
A compartmentalized surface model of Nambu and Goto is studied on triangulated spherical surfaces by using the canonical Monte Carlo simulation technique. One-dimensional bending energy is defined on the skeletons and at the junctions, and…
In this Thesis we develop the geometric formulations for higher-order autonomous and non-autonomous dynamical systems, and second-order field theories. In all cases, the physical information of the system is given in terms of a Lagrangian…
We point out that the determination of the leptonic decay width of radially-excited quarkonia is strongly dependent on the position of the node typical of these excitations. We suggest that this feature could be related with the…
In the framework of metric-like approach, totally symmetric arbitrary spin bosonic conformal fields propagating in flat space-time are studied. Depending on the values of conformal dimension, spin, and dimension of space-time, we classify…
Dynamical symmetry breaking is investigated for a four-fermion Nambu-Jona-Lasinio model in external electromagnetic and gravitational fields. An effective potential is calculated in the leading order of the large-N expansion using the…
Medium modifications of the pion-omega-rho vertex are analyzed in context of the omega -> pi gamma* and rho -> pi gamma* decays in nuclear matter. A relativistic hadronic model with mesons, nucleons, and Delta(1232)isobars is applied. A…
Starting with the polarization dependent Wigner function of vector mesons, we derive an expression for the 00-component ($\rho_{00}$) of spin density matrix in terms of the second order gradients of the vector meson distribution functions.…
A novel strategy to handle divergences typical of perturbative calculations is implemented for the Nambu--Jona-Lasinio model and its phenomenological consequences investigated. The central idea of the method is to avoid the critical step…
We review the recent results on development of vector models of spin and apply them to study the influence of spin-field interaction on the trajectory and precession of a spinning particle in external gravitational and electromagnetic…
The most general N=1 Lagrangian for the spinning particle with local supersymmetry is found and the constraints of the system are analysed. The Dirac quantisation of the model is also investigated.
We use heavy vector meson $SU(2)_L \times SU(2)_R$ chiral perturbation theory to predict differential decay distributions for $\tau \rightarrow \rho \pi \nu_\tau$ and $\tau \rightarrow K^* \pi \nu_\tau$ in the kinematic region where $p_V…
Use of the effective Lagrangian incorporating both the scalar and pseudoscalar mesons gives a possibility to calculate the $\pi \pi$-scattering lengths without attraction of the ChPT theory.