Fermion localization and resonances on two-field thick branes

TL;DR

This paper investigates how fermions can be localized on two-field thick branes in higher-dimensional spacetime, analyzing the effects of a specific Yukawa coupling and identifying resonant fermionic modes linked to the brane's internal structure.

Contribution

It introduces a detailed analysis of fermion localization on two-field branes with a novel Yukawa coupling, revealing the presence of resonances associated with brane internal structure.

Findings

Resonant fermionic modes are found for both chiralities.

Fermion localization depends on the brane's internal structure.

The Yukawa coupling $ar ext{ extPsi} ext extphi ext extchi ext extPsi$ facilitates fermion trapping.

Abstract

We consider $(4,1)$-dimensional branes constructed with two scalar fields $\phi$ and $\chi$ coupled to a Dirac spinor field by means of a general Yukawa coupling. The equation of motion for the coefficients of the chiral decomposition of the spinor in curved spacetime leads to a Sch\"odinger-like equation whose solutions allow to obtain the masses of the fermionic modes. The simplest Yukawa coupling $\bar\Psi\phi\chi\Psi$ is considered for the Bloch brane model and fermion localization is studied. We found resonances for both chiralities and related their appearance to branes with internal structure.