Ultraviolet Running Constraints on Low Mass Dark Sectors

TL;DR

This paper investigates the ultraviolet constraints on low mass dark matter models with a dark U(1) sector, focusing on the running of scalar couplings and the implications of Landau poles for model viability and collider constraints.

Contribution

It provides a detailed analysis of the UV behavior of scalar couplings in dark U(1) models and links Landau pole constraints to experimental bounds from the LHC.

Findings

Landau poles occur at lower energies than gauge couplings.

Current LHC constraints limit the dark gauge coupling to about 0.5-1.

Smaller gauge couplings (~0.15) are preferred for Majorana dark matter.

Abstract

We analyze the UV breakdown of Sub-GeV dark matter models that live in a new, dark U(1) sector. Many of these models include a scalar field, which is either the dark matter itself or a dark Higgs field that generates mass terms for the dark matter particle via spontaneous symmetry breaking. A quartic self coupling of this scalar field is generically allowed, and we show that its running is largely governed by the strength of the U(1) gauge field, $\alpha_D$. Furthermore, it consistently has a lower Landau pole than the gauge coupling. Link fields, which couple to both the dark sector and the Standard Model (SM), connect these Landau poles to constraints on SM charged particles. Current LHC constraints on link fields are compatible with $\alpha_D \lesssim 0.5 - 1$ for most of the mass range in most models, while smaller values, $\alpha_D \lesssim 0.15$, are favored for Majorana DM.