相关论文: Electroweak Strings: A Progress Report

We show that the electroweak $Z-$string can be stabilized by the presence of bound states of a complex scalar field. We argue that fermions coupled to the scalar field of the string can also make the string stable and discuss the physical…

The vortex solution (Z-string) of the electroweak interactions can be interpreted as the 2-dimensional sphaleron at the top of a non-contractible sphere. The same holds for another type of solution, the W-string.

We describe electroweak strings and their ability to carry Chern-Simons number. Certain string configurations, for any $\theta_W$, carry Chern-Simons number equal to that of the sphaleron and we conjecture that such strings are ``extended…

We give a prescription for embedding classical solutions and, in particular, topological defects in field theories which are invariant under symmetry groups that are not necessarily simple. After providing examples of embedded defects in…

In the context of electroweak strings, the baryon number anomaly equation may be reinterpreted as a conservation law for baryon number minus helicity. Since the helicity is a sum of the link and twist numbers, linked or twisted loops of…

We give a detailed stability analysis of the Z-string in the standard electroweak model. We identify the mode that determines the stability of the string and numerically map the region of parameter space where the string is stable. For…

We show that the sphaleron energy which identifies with the (instanton) potential barrier for B-violation is reduced in the presence (background) of an electroweak Z-string. We also show that for large enough Higgs coupling, $\lambda$, the…

We review a class of non-topological defects in the standard electroweak model, and their implications. Starting with the semilocal string, which provides a counterexample to many well known properties of topological vortices, we discuss…

We show that the Z-strings of the standard electroweak theory can be stabilized by strong external magnetic fields, provided that $\beta^{1/2} \equiv M_H/M_Z\leq 1$, where $M_H$ and $M_Z$ are the Higgs and Z masses. The magnetic fields…

I report on a critical analysis of the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This mechanism relies upon electroweak symmetry restoration in a region around cosmic strings, where sphalerons would…

We investigate the stability of the electroweak Z-string at high temperatures. Our results show that while finite temperature corrections can improve the stability of the Z-string, their effect is not strong enough to stabilize the Z-string…

We study the quantum energy of the Z-string in 2+1 dimensions using the phase shift formalism. Our main interest is the question of stability of a Z-string carrying a finite fermion number.

The stability of "visible" electroweak-type cosmic strings is investigated in an extension of the Standard Model (SM) by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The "visible" and dark…

Classical solutions describing strings endowed with an electric charge and carrying a constant electromagnetic current are constructed within the bosonic sector of the Electroweak Theory. For any given ratio of the Higgs boson mass to W…

We investigate the instabilities of low winding number electroweak strings using standard numerical techniques of linear algebra. For strings of unit winding we are able to confirm and extend existing calculations of the unstable region in…

We show that the minimal supergravity extension of the standard model automatically contains topologically stable electroweak strings if the hidden sector is invariant under the exact R-symmetry. These defects appear in the form of the…

The electroweak sphaleron is a static, unstable solution of the Standard Model classical field equations, representing the energy barrier between topologically distinct vacua. In this work, we present a comprehensive updated analysis of the…

We discuss the stability of an electroweak string with axions in its core, which give to the configuration a quasi-topological property, and compare it with other modifications using instantons in the thin wall approximation.

A solution of the standard electroweak theory with a single lepton family is constructed, consisting of a cosmic string and a fermion condensate within its core. The stability of this system to small perturbations is examined, and it is…

We map the parameter space that leads to stable Z-vortices in the electroweak model. For $sin^2 \theta_W = 0.23$, we find that the strings are unstable for a Higgs mass larger than 24 GeV. Given the latest constraints on the Higgs mass from…