Low-Energy Signals from Kinetic Mixing with a Warped Abelian Hidden Sector

TL;DR

This paper explores the phenomenology of a light Abelian hidden sector in a warped extra dimension, focusing on the Kaluza-Klein vectors' decay properties, experimental bounds, and potential for discovery in low-energy experiments.

Contribution

It introduces a detailed analysis of a warped hidden sector with a Kaluza-Klein tower, including decay properties and experimental bounds, advancing understanding of extra-dimensional signals.

Findings

Viable parameter space for hidden vectors in meson factories.

Significant production rates for hidden Kaluza-Klein vectors in experiments.

Potential to probe extra dimensions with low-energy experiments.

Abstract

We investigate the detailed phenomenology of a light Abelian hidden sector in the Randall-Sundrum framework. Relative to other works with light hidden sectors, the main new feature is a tower of hidden Kaluza-Klein vectors that kinetically mix with the Standard Model photon and Z. We investigate the decay properties of the hidden sector fields in some detail, and develop an approach for calculating processes initiated on the ultraviolet brane of a warped space with large injection momentum relative to the infrared scale. Using these results, we determine the detailed bounds on the light warped hidden sector from precision electroweak measurements and low-energy experiments. We find viable regions of parameter space that lead to significant production rates for several of the hidden Kaluza-Klein vectors in meson factories and fixed-target experiments. This offers the possibility of exploring the structure of an extra spacetime dimension with lower-energy probes.