Probing Hidden Sectors with St\"uckelberg U(1) Gauge Fields

TL;DR

This paper introduces a framework where visible matter interacts with hidden sectors via St"uckelberg U(1) gauge fields, allowing broad Z' choices and sizable interactions without exotic matter, with potential string theory embeddings.

Contribution

It presents a novel mechanism for visible-hidden matter interactions through St"uckelberg U(1) gauge fields, expanding Z' model possibilities without exotic matter.

Findings

Broadened Z' gauge boson options without exotic matter

Potential for sizable tree-level visible-hidden interactions

Discussion of string theory embeddings and phenomenology

Abstract

We propose a framework in which visible matter interacts with matter from a hidden sector through mass mixings of St\"uckelberg U(1) gauge fields. In contrast to other Z' mediation scenarios, our setup has the added appealing features that (i) the choice of Z's can be significantly broadened without necessarily introducing unwanted exotic matter and (ii) there can be sizable tree-level interactions between the visible and hidden sectors. String theory embeddings of this scenario and their phenomenological features are briefly discussed.