Fermion localization in higher curvature and scalar-tensor theories of gravity

TL;DR

This paper investigates how higher curvature F(R) gravity influences fermion localization in a five-dimensional warped spacetime, showing that it affects the localization of massless and massive fermions and has implications for collider phenomenology.

Contribution

It demonstrates the impact of higher curvature terms on fermion localization profiles and establishes their equivalence with scalar-tensor models, affecting collider signatures.

Findings

Massless chiral fermions localize near the TeV brane.

Massive KK fermions localize towards the Planck brane.

Higher curvature effects do not produce detectable signatures in collider experiments.

Abstract

It is well known that in a braneworld model, the localization of fermions on lower dimensional submanifold (say a TeV 3-brane) is governed by the gravity in the bulk which also determines the corresponding phenomenology on the brane. Here we consider a five dimensional warped spacetime where the bulk geometry is governed by higher curvature like F(R) gravity. In such a scenario, we explore the role of higher curvature terms on the localization of bulk fermions which in turn determines the effective radion-fermion coupling on the brane. Our result reveals that for appropriate choices of the higher curvature parameter, the profiles of the massless chiral modes of the fermions may get localized near TeV brane while that for massive Kaluza-Klein (KK) fermions localize towards the Planck brane. We also explore these features in the dual scalar-tensor model by appropriate transformations. The localization property turns out to be identical in both the models. This rules out the possibility of any signature of massive KK fermions in TeV scale collider experiments due to higher curvature gravity effects.