Related papers: Stability of an electroweak string with a fermion …
Technicolor and other theories of dynamical electroweak symmetry breaking invoke chiral symmetry breaking triggered by strong gauge-dynamics, analogous to that found in QCD, to explain the observed W, Z, and fermion masses. In this talk we…
The causal action principle is analyzed for a system of relativistic fermions composed of massive Dirac particles and neutrinos. In the continuum limit, we obtain an effective interaction described by classical gravity as well as the strong…
B-decays mediated by both charged currents and neutral currents have provided hints of violation of lepton flavour universality. By assuming an explanation of these anomalies in terms of new physics at the TeV scale affecting the third…
We show that there exist massive perturbative states of the ten dimensional Green-Schwarz closed superstring that are stabilized against collapse due to presence of fermionic zero modes on its worldsheet. The excited fermionic degrees of…
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…
The aim of the thesis is to study models of the electroweak symmetry breaking caused by dynamically generated masses of quarks and leptons. (1) We perform the basic analysis whether the main underlying idea, that the masses of only known…
We study the spectrum of fermionic modes on cosmic string loops. We find no fermionic zero modes nor massive bound states - this implies that vortons stabilized by fermionic currents do not exist. We have also studied kink-(anti)kink and…
We explore the Higgs-Gauge configuration space in the standard electroweak theory. We outline a general prescription that uses the non-trivial topology associated with the gauge group of the theory, to find known solutions of the Euclidean…
We examine neutrino zeromode solutions on the electroweak $Z$-string and their effect on the stability of the string in the standard model and its extensions. We propose using topological invariants constructed from the momentum (and real)…
It is known that the Schwinger mechanism of vector-like QED theory is afflicted by a logarithmic singularity under background electromagnetic field due to a hypothetical massless charged fermion. We extend singularity analysis to a more…
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 use large-scale numerical simulations to study the formation and evolution of non-topological defects in a generalized electroweak phase transition described by the Glashow-Salam-Weinberg model without fermions. Such defects include…
The question of classical topological stability of the gauge vortex defects is reanalyzed upon taking into account the quantum perturbative effects. The purely Abelian Higgs string remains stable while the coupling of the effectively…
If the electroweak symmetry is broken by some unspecified strong dynamics, composite fermions may exist with definite transformation properties under SU(2)_L x SU(2)_R/SU(2)_{L+R} and may play a role in giving masses by mixing to all the…
It is well known that the Standard Model of the Electroweak interactions rests on a metastable vacuum. This can only be fixed by means of new physics. Presently neutrino physics provides the most intriguing framework to formulate new…
The stability of scalar quintessence potentials under quantum fluctuations is investigated for both uncoupled models and models with a coupling to fermions. We find that uncoupled models are usually stable in the late universe. However, the…
I present two interesting studies related to the role of solitons in theories with spontaneous symmetry breaking. Quantised fermions coupled to solitons are known to induce fractional fermion number. I present an example where an unstable…
If the standard model of quarks and leptons is extended to include three singlet right-handed neutrinos, then the resulting fermion structure admits an infinite number of anomaly-free solutions with just one simple constraint. Well-known…
The stability of scalar quintessence potentials under quantum fluctuations is investigated both for uncoupled models and models with a coupling to fermions. We find that uncoupled models are usually stable in the late universe. However, a…
We consider a set of gauge invariant terms in higher order effective Lagrangians of the strongly interacting scalar of the electroweak theory. The terms are introduced in the framework of the hidden gauge symmetry formalism. The usual gauge…