Related papers: Embedded Defects
The standard electroweak theory admits a string solution, the Z string, in which only the electrically neutral Higgs fields are excited. This solution is unstable at zero temperature: Z strings decay by exciting charged Higgs modes. In the…
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…
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…
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…
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 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…
I describe the string solutions in the standard electroweak model and argue that they may be stabilized by quark, lepton or other bound states. I then reinterpret the sphaleron in terms of electroweak strings and show that it can be viewed…
We explicitly show the analogy between the symmetry breaking scheme for the GUT flipped $SU(5)$ with that of the Weinberg-Salam theory of electroweak interactions. This allows us to construct the embedded defect spectrum of the theory…
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…
Z-strings in the Weinberg-Salam model including fermions are unstable for all values of the parameters. The cause of this instability is the fermion vacuum energy in the Z-string background. Z-strings with non-zero fermion densities,…
Stability and instability bands in classical mechanics are well-studied in connection with systems such as described by the Mathieu equation. We examine whether such band structure can arise in classical field theory in the context of an…
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 examine the Standard Model field configurations near cosmic strings in a particular class of models. This class is defined by the condition that the generator of the flux in the string, $T_s$, commutes with the Standard Model Lie…
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…
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…
Z-strings in the Weinberg-Salam model including fermions are unstable for all values of the parameters. The cause of this instability is the fermion vacuum energy in the Z-string background. Z-strings with non-zero fermion densities,…
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 propose a criterion to classify hybrid defects occurring in field theoretic models such as the standard electroweak model. This criterion leads us to consider the minimal extension of the electroweak model in which electroweak magnetic…
In this paper we describe a new type of topological defect, called a homilia string, which is stabilized via interactions with the string network. Using analytical and numerical techniques, we investigate the stability and dynamics of…
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…