# Fermions localization on de Sitter branes

## TL;DR

This paper investigates how spin-1/2 fermions can be localized on a de Sitter brane within a five-dimensional spacetime, revealing a spectrum with a mass gap and both bound and resonant states influenced by Yukawa coupling.

## Contribution

It demonstrates the localization of a single massless chiral fermion mode and characterizes the massive spectrum, including the effects of Yukawa coupling and the mass gap in an asymmetric de Sitter brane scenario.

## Key findings

- Only one massless chiral mode is localized on the brane.
- Massive modes form a spectrum with a mass gap determined by Yukawa coupling.
- Resonant modes exist above the mass gap for both chiralities.

## Abstract

Spin 1/2 fields localization on an asymmetric dS${}_4$ scenario, where the brane interpolates between two spacetimes dS${}_5$ and AdS${}_5$, is determined. The bulk spinor is coupled to scalar field of the brane by a nonminimal Yukawa term compatible with the scenario's geometry. We show that, independently of wall's thickness, only one massless chiral mode is localized on the wall. The massive chiral modes follow a Schr\"odinger equation, whose potential has a mass gap determined by Yukawa constant, which is a generic property of this system. The fermions spectrum is defined bellow the gap, by bound states of both chiralities with the same mass, and above the gap, by a continuous spectrum with local and global resonant modes of both chiralities and different mass.