Domain wall brane in squared curvature gravity

TL;DR

This paper proposes a thick brane model within squared curvature gravity, demonstrating gravity localization and fermion trapping, with potential applications in higher-dimensional theories of our universe.

Contribution

It introduces a novel thick brane model in squared curvature gravity and explores fermion localization mechanisms with specific scalar couplings.

Findings

Gravity zero mode is normalizable, reproducing 4D gravity.

Fermion zero modes are localized for left-handed fermions.

Massive KK fermion states can be trapped as resonances or bound states.

Abstract

We suggest a thick braneworld model in the squared curvature gravity theory. Despite the appearance of higher order derivatives, the localization of gravity and various bulk matter fields is shown to be possible. The existence of the normalizable gravitational zero mode indicates that our four-dimensional gravity is reproduced. In order to localize the chiral fermions on the brane, two types of coupling between the fermions and the brane forming scalar is introduced. The first coupling leads us to a Schr\"odinger equation with a volcano potential, and the other a P\"oschl-Teller potential. In both cases, the zero mode exists only for the left-hand fermions. Several massive KK states of the fermions can be trapped on the brane, either as resonant states or as bound states.