Domain wall generation by fermion self-interaction and light particles

Abstract

A possible explanation for the appearance of light fermions and Higgs bosons on the four-dimensional domain wall is proposed. The mechanism of light particle trapping is accounted for by a strong self-interaction of five-dimensional pre-quarks. We obtain the low-energy effective action which exhibits the invariance under the so called τ -symmetry. Then we find a set of vacuum solutions which break that symmetry and the five-dimensional translational invariance. One type of those vacuum solutions gives rise to the domain wall formation with consequent trapping of light massive fermions and Higgs-like bosons as well as massless sterile scalars, the so-called branons. The induced relations between lowenergy couplings for Yukawa and scalar field interactions allow to make certain predictions for light particle masses and couplings themselves, which might provide a signature of the higher dimensional origin of particle physics at future experiments. The manifest translational symmetry breaking, eventually due to some gravitational and/or matter fields in five dimensions, is effectively realized with the help of background scalar defects. As a result the branons acquire masses, whereas the ratio of Higgs and fermion (presumably top-quark) masses can be reduced towards the values compatible with the present-day phenomenology. Since the branons do not couple to fermions and the Higgs bosons do not decay into branons, the latter ones are essentially sterile and stable, what makes them the natural candidates for the dark matter in the Universe.

New localization method of U (1) gauge vector field on flat branes in (asymptotic) AdS 5 spacetime

“…(3.7) can be further factored as (−∂ z −α) (∂ z −α) ρ n (z) = m 2 n ρ n (z). (3.11) This is the supersymmetry quantum mechanics form of the Schrödinger equation (3.7) [47], which guarantees the positivity of m 2 n . Therefore, the tachyonic vector modes are excluded.…”

Fermions in 5D brane world models

“…The fields ψ L and ψ R are localized in the vicinity of the same point in the extra dimension because they have the same wave function; taken together they make up a four-dimensional Dirac fermion with mass M. Depending on the form of the function F(z), the zero mode can be localized at any point of the orbifold (see, for example, [3,5,7]). In order to decouple equations (6) and (7) for (e σ G) 0, first let us consider the left-handed parts of the spinor fields Ψ…”

Thick branes from self-gravitating scalar fields

“…The gravity happens to play an important role in a (de) localization of matter fields. [2,3,4,5,6] In this work we consider a model of the domain wall formation with finite thickness ("thick" branes)in fivedimensional noncompact space-time by the scalar matter minimally coupled to gravity [7], [8]. The scalar matter is assumed to consist of two fields with O(2) symmetric self interaction and with manifest O(2) symmetry breaking by terms quadratic in fields.…”