Fat brane, dark matter and localized kinetic terms in six dimensions

Ricardo G Landim

doi:10.1140/epjc/s10052-020-7697-0

Abstract

Extra dimensions (ED) have been used as attempts to explain several phenomena in particle physics over the years. In this paper we investigate the role of an abelian gauge field as mediator of the interaction between dark matter (DM) and Standard Model (SM) particles, in a model with two flat and transverse ED compactified on the chiral square. DM is confined in a thin brane, localized at the origin of the chiral square, while the SM is localized in a finite width brane, lying in the opposite corner of the square. A brane-localized kinetic term is present in the DM brane, while in the fat brane it is not allowed. In this model the kinetic mixing is not required because we assume that the SM particles couple to the mediator through their B-L charges, while DM couples to it via a dark charge. Assuming a complex scalar field as DM candidate it is possible to obtain the observed DM relic abundance and avoid direct detection constraints for some parameter choices.

Highlights

Interacting massive particles (WIMPs) have been the most well-known dark matter (DM) candidates [1] for decades, but the absence of any trace encourage us to look for different scenarios, both experimentally and theoretically
In this paper we investigate the role of an abelian gauge field as mediator of the interaction between dark matter (DM) and Standard Model (SM) particles, in a model with two flat and transverse Extra dimensions (ED) compactified on the chiral square
It is expected to have brane-localized-kinetic term (BLKT) in both thin and thick branes, one may investigate the case where the BLKT inside the fat brane is very small and can be neglected. This is the aim of this paper, where we show that it is possible to have a vector field in the bulk, which mediates the interaction between the SM particles localized in the fat brane and a DM candidate confined in a thin brane, without employing a kinetic-mixing term

Summary

Introduction

Interacting massive particles (WIMPs) have been the most well-known dark matter (DM) candidates [1] for decades, but the absence of any trace encourage us to look for different scenarios, both experimentally and theoretically. A relatively recent and very explored idea is the possible interaction between DM and SM via a new dark U (1)D gauge field, arising in turn from a kinetic mixing term between this new vector mediator (called dark photon, DP) and the hypercharge U (1)Y field [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]. It is expected to have BLKT in both thin and thick branes, one may investigate the case where the BLKT inside the fat brane is very small and can be neglected This is the aim of this paper, where we show that it is possible to have a vector field in the bulk, which mediates the interaction between the SM particles localized in the fat brane and a DM candidate confined in a thin brane, without employing a kinetic-mixing term. We examine the constraints on the SM interactions with the DM particle from both direct and indirect observations in Sect, 4, while Sect. 5 is reserved for conclusions

Vector mediator in the bulk

Interactions

Constraints from observations and experiments

Conclusions