Fermion localization on asymmetric two-field thick branes

Abstract

In this paper we investigate the localization of fermions on asymmetric thick branes generated by two scalars $\varphi$ and $\chi$. In order to trap fermions on the asymmetric branes with kink-like warp factors, the couplings with the background scalars $\eta \bar{\Psi }F(\chi ,\varphi )\Psi$ are introduced, where $F(\chi ,\varphi )$ is a function of $\varphi$ and $\chi$. We find that the coupling $\eta \bar{\Psi }\chi \varphi \Psi$ do not support the localization of 4-dimensional fermions on the branes. While, for the case $\eta \bar{\Psi }\chi \Psi +{\eta }^{\prime }\bar{\Psi }\varphi \Psi$, which is the kink-fermion coupling corresponding to one-scalar-generated brane scenarios, the zero mode of left-handed fermions could be trapped on the branes under some conditions.

Comments: v2: 11 pages, 4 figures, accepted by CQG