Fermion Resonances on a Thick Brane with a Piecewise Warp Factor

TL;DR

This study investigates fermion resonances on a thick brane with a piecewise warp factor, analyzing how brane parameters and scalar-fermion couplings affect resonance properties like mass, width, and lifetime.

Contribution

It introduces a model with a piecewise warp factor for thick branes and explores fermion resonances with generalized Yukawa couplings, revealing effects of brane structure and parameters on resonance behavior.

Findings

Resonant states appear even in branes without internal structure.

Scalar-fermion coupling influences resonance characteristics.

Brane thickness affects the resonance properties of KK fermions.

Abstract

In this paper, we mainly investigate the problems of resonances of massive KK fermions on a single scalar constructed thick brane with a piecewise warp factor matching smoothly. The distance between two boundaries and the other parameters are determined by one free parameter through three junction conditions. For the generalized Yukawa coupling $\eta\bar{\Psi}\phi^{k}\Psi$ with odd $k=1,3,5,...$, the mass eigenvalue $m$, width $\Gamma$, lifetime $\tau$, and maximal probability $P_{max}$ of fermion resonances are obtained. Our numerical calculations show that the brane without internal structure also favors the appearance of resonant states for both left- and right-handed fermions. The scalar-fermion coupling and the thickness of the brane influence the resonant behaviors of the massive KK fermions.