Sergey V. Troitsky

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In many theories with flat directions of scalar potential, static vortex solutions do not exist for a generic choice of vacuum. In two Euclidean dimensions, we find their substitutes — constrained instantons consisting of compact core formed by Abrikosov– Nielsen–Olesen vortex and long-ranged cloud of modulus field. In (3+1) dimensions, an initial compact(More)
Previous studies have shown how the three generations of the Standard Model fermions can arise from a single generation in more than four dimensions, and how off-diagonal neutral couplings arise for gauge-boson Kaluza-Klein recurrences. These couplings conserve family number in the leading approximation. While an existing example, built on a spherical(More)
It has been shown recently that the amplitude of the creation of n real scalar particles by one virtual boson near n–particle threshold exhibits exponential behavior at n ∼ 1/λ. We extend this result to the processes of multiparticle production at threshold by two virtual bosons. We find that both the tree–level amplitude and leading–n loop corrections have(More)
In 5+1 dimensions, we construct a vortex-like solution on a two-dimensional sphere. We study fermionic zero modes in the background of this solution and relate them to the replication of fermion families in the Standard Model. In particular, using a compactified space removes the need for the difficult localisation of gauge fields, while the present(More)
We develop an approach to the origin of three generations of the Standard Model fermions from one generation in a higher-dimensional theory, where fourdimensional fermions appear as zero modes trapped in the core of a topological defect, and the hierarchy of masses and mixings is produced by wave function overlaps in extra dimensions. We present a model(More)
We calculate probabilities of flavour violating processes mediated by KalutzaKlein modes of gauge bosons in a model where three generations of the Standard Model fermions arise from a single generation in (5+1) dimensions. We discuss a distinctive feature of the model: while the processes in which the generation number G changes are strongly suppressed, the(More)
Three fermionic generations on a topological defect in extra dimensions. We suggest a mechanism explaining the origin of three generations of the Standard Model fermions from one generation in a higher-dimensional theory. Four-dimensional fermions appear as zero modes trapped in the core of a topo-logical defect with topological number three. We discuss(More)
Naturally small Majorana neutrino masses arise from nonstandard supersymmetry breaking terms. This mechanism works in the minimal supersymmetric framework and does not require extra particles or new mass scales. E-mail: frere@ulb.ac.be E-mail: ml@ms2.inr.ac.ru E-mail: st@ms2.inr.ac.ru In realistic models of broken supersymmetry, two scales usually appear.(More)
Astrophysical sources of energetic gamma rays provide the right conditions for maximal mixing between (pseudo)scalar (axion-like) particles and photons if their coupling is strong enough. This is independent of whether or not the axion interaction is standard at all energies or becomes suppressed in the extreme conditions of the stellar interior. The flux(More)