Related papers: Is the $\sigma$ meson dynamically generated?

The sine-Gordon model is studied with model parameters that depend on both space and time. An effective model with one degree of freedom is constructed, allowing the description of the kink movement in both a temporally non-autonomous and…

We study the decay of dynamically generated resonances from the interaction of two vectors into a $\gamma$ and a pseudoscalar meson. The dynamics requires anomalous terms involving vertices with two vectors and a pseudoscalar, which renders…

We study the non-perturbative phenomena of Dynamical Mass Generation and Confinement by truncating at the non-perturbative level the Schwinger-Dyson equations in Maxwell-Chern-Simons planar quantum electrodynamics. We obtain numerical…

We consider the resonant production of fermions from an oscillating axial background. The classical evolution of the axial field is given by that of a massive pseudovector field, as suggested by the renormalizability of the theory. We look…

It is generally assumed that the dynamical generation of the Higgs mass parameter of the superpotential, $\mu$, implies the existence of a light singlet at or below the supersymmetry breaking scale, $\msusy$. We present a counter-example in…

The linear sigma model with pions and sigma coupled to baryons and a (massive) gauge vector meson is considered for the description of a finite baryonic density system. The stability equation for the bound system is studied in the…

We show, in a simple quantum mechanical model, how a theory can become supersymmetric in the presence of interactions even when the free theory is not. This dynamical generation of supersymmetry relaxes the condition on the equality of…

The vacuum energy density is obtained for the $O(N)$ nonlinear sigma model. It is shown that non-perturbative contributions are connected with the square of the symmetry current of the group $O(N)$. This result is valid for $\sigma$- fields…

The linear sigma model at finite baryonic density with a massive vector field is investigated considering that all the bosonic fields develop non zero expected classical values, eventually associated to condensates and corresponding to…

We construct a quantum system of spherical spins with a continuous local symmetry. The model is exactly soluble in the thermodynamic limit and exhibits a number of interesting properties. We show that the local symmetry is spontaneously…

The quantum models of a massive scalar particle inside of an open bag generated by a pseudo-Gaussian conformaly flat (1+1) metrics are investigated. The potential of a free moving test particle, in the generated metric, has Gaussian…

In order to explore a possible dynamical nature for the Higgs field (such as its being a pseudo-Goldstone boson) we develop a renormalizable Lagrangian based on the minimal $SO(5)$ linear $\sigma$-model with the symmetry softly broken to…

We study an N=1 two-dimensional non-linear sigma model with boundaries representing, e.g., a gauge fixed open string. We describe the full set of boundary conditions compatible with N=1 superconformal symmetry. The problem is analyzed in…

After explicitly constructing the symmetric space sigma model lagrangian in terms of the coset scalars of the solvable Lie algebra gauge in the current formalism we derive the field equations of the theory.

The string tension does not have to be put in by hand, it can be dynamically generated, as in the case when we formulate string theory in the modified measure formalism, and other formulations as well. Then string tension appears, but as an…

We show that two-dimensional sigma models are equivalent to certain perturbed conformal field theories. When the fields in the sigma model take values in a space G/H for a group G and a maximal subgroup H, the corresponding conformal field…

We investigate the dynamical system generated by the function $\lfloor\lambda x\rfloor$ defined on $\mathbb R$ and with a parameter $\lambda\in \mathbb R$. For each given $m\in \mathbb N$ we show that there exists a region of values of…

Though the classical treatment of spontaneous decay leads to an exponential decay law, it is well known that this is an approximation of the quantum mechanical result which is a non-exponential at very small and large times for narrow…

The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly-compressible, supersonic…

We study the nonlinear $O(N)$ sigma model on $S^2$ with the gravitational coupling term, by evaluating the effective potential in the large-$N$ limit. It is shown that there is a critical curvature $R_c$ of $S^2$ for any positive…