Nonlocal Portal to the Dark Sector

TL;DR

This paper introduces a nonlocal model connecting the Standard Model to the Dark Sector via a Stueckelberg portal, analyzing its phenomenological implications and experimental constraints.

Contribution

It presents a novel nonlocal realization of the Stueckelberg portal, extending the interaction framework between the Standard Model and Dark Sector.

Findings

Constraints on nonlocality scale from meson decay experiments

Predictions for semi-invisible and invisible meson decay channels

Discussion of experimental limits on model parameters

Abstract

We propose a nonlocal realization of the Stueckelberg portal between the Standard Model and Dark Sector, which decouple in the local limit. This implies that the mediator, $U(1)_{\rm D}$ Dark Photon $A'$ with a Stueckelberg mass, interacts nonlocally with the Standard Model quarks and leptons. We study phenomenological implications of this scenario for the meson decays into semi-invisible and invisible channels. We discuss the experimental limitations on the model parameters, including the nonlocality scale.