Searcharxiv⌕ Search

arXiv subjects

HoSeong La

Publications and source records attributed to HoSeong La.

27 records · Page 2Linked to original sources

Vortex Solutions in Two-Higgs Systems and $\tanβ$

Classical vortex solutions in various two-Higgs systems are studied. The systems we consider include the standard model with two Higgs doublets, in which case the vortex appears as part of a string-like object. The Higgs potentials contain several different couplings in general and the spontaneous symmetry breaking involves with two different vacuum expectation values. In particular it is shown that the existence of such a solution in general requires a specific ratio of the two Higgs vacuum expectation values, i.e. $\tanβ$, and some inequalities between different Higgs couplings. This ratio can be determined in terms of the couplings in the Higgs potential. The Higgs masses are also computed in this case. (1+2)-d solutions are topological so that they are topologically stable and the Bogomol'nyi bound is saturated for some couplings. Some comments on the stabilization of (1+3)-d solutions are also given. Thus, as long as such a defect can be formed in the early universe, stable or not, $\tanβ$ is no longer an independent free parameter in the theory.

hep-ph↗

"Vortex Solution in a Multi-Higgs System and Its Physical Implication,"

Classical vortex solutions in $(1+2)$-dimensional multi-Higgs systems are studied. In particular the existence of such a solution requires equal characteristic lengths and a specific relation between the ratio of the two Higgs vacuum expectation values and the couplings in the Higgs potential, if $λ_3\neq 0$.

hep-ph↗

Electroweak Z-string in Two-Higgs-Doublet Standard Model

We derive electroweak Z-string solutions in the Glashow-Weinberg-Salam model with two Higgs doublets. The existence of such solutions in particular requires a specific relation between the ratio of the two Higgs vacuum expectation values, {\it i.e.} $\tanβ$, and the couplings in the Higgs potential.

hep-ph↗

Time-Dependent Dilatonic Domain Walls

Time-dependent domain wall solutions with infinitesimal thickness are obtained in the theory of a scalar field coupled to gravity with the dilaton, i.e. the Jordan-Brans-Dicke gravity. The value of the dilaton is determined in terms of the Brans-Dicke parameter $ω$. In particular, the solutions exist for any $ω>0$ and as $ω\to\infty$ we obtain new solutions in general relativity. They have horizons whose sizes depend on $ω$.

hep-th↗

Dilatonic Domain Walls

Eq.(19) is added and related issues are further clarified. Also some typos and signs a re corrected.

hep-ph↗

Solitons reduced from Heterotic fivebranes

In view of the expectation that the solitonic sector of the lower dimensional world may be originated from the solitonic sector of string theory, various solitonic solutions are reduced from the heterotic fivebrane solutions in the ten-dimensional heterotic string theory. These solitons in principle can appear after proper compactifications, {\it e.g.} toroidal compactifications.

hep-th↗

Sine-Gordon Solitons as Heterotic Fivebranes

The Euclidean analogues of the sine-Gordon solitons are used as sources of the heterotic fivebrane solutions in the ten-dimensional heterotic string theory. Some properties of these soliton solutions are discussed. These solitons in principle can appear as string-like objects in 4-dimensional space-time after proper compactifications.

hep-th↗

String Motion in Fivebrane Geometry

The classical motion of a test string in the transverse space of two types of heterotic fivebrane sources is fully analyzed, for arbitrary instanton scale size. The singular case is treated as a special case and does not arise in the continuous limit of zero instanton size. We find that the orbits are either circular or open, which is a solitonic analogy with the motion of an electron around a magnetic monopole, although the system we consider is quantitatively different. We emphasize that at long distance this geometry does not satisfy the inverse square law, but satisfies the inverse cubic law. If the fivebrane exists in nature and this structure survives after any proper compactification, this last result can be used to test classical ``stringy'' effects.

hep-th↗

Orbits of a String around a Fivebrane

The classical orbits of a test string in the transverse space of a singular heterotic fivebrane source are classified. The orbits are found to be either circular or open, but not conic because the inverse square law is not satisfied at long range. This result differs from predictions of General Relativity. The conserved total angular momentum contains an intrinsic component from the fivebrane source, analogous to the electron-monopole case.

hep-th↗