相关论文: Criterion for dynamical chiral symmetry breaking
The isovector--vector and the isovector--axial-vector current are related by a chiral transformation. These currents can be called chiral partners at the fundamental level. In a world where chiral symmetry was not broken, the corresponding…
We discuss spontaneously broken quantum field theories with a continuous symmetry group via the constraint effective potential. Employing lattice simulations with constrained values of the order parameter, we demonstrate explicitly that the…
We discuss scalar mesons properties on the light of chiral dynamics. Considering them as the chiral partners of pseudo-scalar mesons we propose an explanation to their unusual properties based on non-trivial vacuum effects coming from the…
Simple quark models for the low lying vector mesons suggest a mixing between the u- and d-flavors and a violation of the isospin symmetry for the rho-omega system much stronger than observed. It is shown that the chiral dynamics, especially…
Dyson-Schwinger equations furnish a Poincare' covariant framework within which to study hadrons. A particular feature is the existence of a nonperturbative, symmetry preserving truncation that enables the proof of exact results. The gap…
Schwinger-Dyson equations are used to study spontaneous chiral and parity symmetry breaking of three dimensional quantum electrodynamics with two-component fermions. This theory admits a topological photon mass that explicitly breaks parity…
I discuss how anomalies affect classical symmetries and how, in turn, the non-trivial nature of the gauge theory vacuum makes these quantum corrections troublesome. Although no solution seems in sight for the cosmological constant problem,…
The relative equilibria of a symmetric Hamiltonian dynamical system are the critical points of the so-called augmented Hamiltonian. The underlying geometric structure of the system is used to decompose the critical point equations and…
We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric…
We incorporate chiral symmetry breaking in a soft-wall version of the AdS/QCD model by using a modified dilaton profile and a quartic term in the bulk scalar potential. This allows one to separate the dependence on spontaneous and explicit…
The problem of dynamical chiral symmetry breaking (DCSB) in multidimensional quantum electrodynamics (QED) is considered. It is shown that for six-dimensional QED the phenomenon of DSCB exists in ladder model for any coupling.
Chiral symmetry breaking patterns are investigated in the U_L(n)xU_R(n) meson model. It is shown that new classes of minima of the effective potential belonging to the center of the Lie algebra exist for arbitrary flavor number n. The true…
We describe a (first, to the best of our knowledge) essentially soluble example of dynamical symmetry breaking phenomenon in a 3+1 dimensional gauge theory without fundamental scalar fields: QED in a constant magnetic field.
An intriguing feature of the Standard Model is that the representations of the unbroken gauge symmetries are vector-like whereas those of the spontaneously broken gauge symmetries are chiral. Here we provide a toy model which shows that a…
Inhomogeneous pseudoscalar and scalar Bethe-Salpeter equations solved using a renormalisation-group-improved rainbow-ladder truncation exhibit bound state poles below and above T_c, the critical temperature for chiral symmetry restoration.…
Supersymmetry breaking by the quantum deformation of a classical moduli space is considered. A simple, non-chiral, renormalizable model is presented to illustrate this mechanism. The well known, chiral, $SU(3) \times SU(2)$ model and its…
We construct a model to study the impact of instantons on the low lying eigenvalue spectrum of the Dirac operator. The model is by necessity, approximate, though it does incorporate the important symmetries of the underlying field theory.…
Chiral dynamics is investigated using the chiral confining Lagrangian (CCL), previously derived from QCD with confinement interaction. Based on the calculations of the quark condensate, which is defined entirely by confinement in the zero…
We study spontaneous symmetry breaking in one dimensional quantum mechanical problems in terms of two-point boundary problems which lead to singular potentials containing Dirac delta functions and its derivatives. We search for…
A formalism is developed to enable the construction of the effective action and related quantities in QED for the case of time-varying background electric fields. Some examples are studied and evidence is sought for a possible transition to…