相关论文: STABILITY OF Z-STRINGS IN STRONG MAGNETIC FIELDS

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 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…

In this Letter we reanalyse the question of the origin of magnetic fields during the electroweak phase transition. We show that their formation is intimately connected to some semiclassical configurations of the gauge fields, such as…

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 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…

In the minimal standard model we discuss stability of the Z-string configuration, which includes the zero mode connected with the broken gauge symmetry. The zero mode induces charge and current on the string and gives backreaction to the…

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…

In the standard model with two Higgs doublets it is shown that the existence of the electroweak Z-string in general requires the same characteristic length for the two Higgs fields as well as a specific ratio of the two Higgs vacuum…

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…

The confinement of quarks in hadrons occurs due to formation of QCD string. At large separation between the quarks the QCD string breaks into pieces due to light quark-antiquark pair creation. We argue that there exist a critical background…

We investigate the standard model in a cosmic string background and show that the electroweak symmetry is partially restored. For a range of parameters the electroweak Higgs field can wind in this region, producing an electroweak string…

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…

We study exact string backgrounds representing a constant magnetic field background in heterotic string theory. These backgrounds are obtained by Kaluza-Klein reduction of a special class of plane wave solutions. For small values of the…

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…

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 consider open strings in an external constant magnetic field $H$. For an (infinite) sequence of critical values of $H$ an increasing number of (highest spin component) states lying on the first Regge trajectory becomes tachyonic. In the…

Semilocal and electroweak strings are well-known to be unstable against unwinding by the condensation of the second Higgs component in their cores. A large class of current models of dark matter contains dark scalar fields coupled to the…

We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their…

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…

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,…