Pure-glue hidden valleys through the Higgs portal

TL;DR

This paper explores how the Higgs boson can connect the Standard Model to a hidden pure-glue sector, leading to diverse hidden glueball decays with potential signatures at the LHC.

Contribution

It extends previous hidden valley models by including Higgs portal couplings, analyzing their effects on hidden glueball decays and lifetimes.

Findings

Hidden glueballs can decay into fermion pairs or via cascade decays involving Higgs emission.

Effective operators induce a wide range of glueball lifetimes and decay modes.

Most operators are not constrained by current electroweak precision tests, allowing experimental exploration.

Abstract

We consider the possibility that the Higgs boson can act as a link to a hidden sector in the context of pure-glue hidden valley models. In these models the standard model is weakly coupled, through loops of heavy messengers fields, to a hidden sector whose low energy dynamics is described by a pure-Yang-Mills theory. Such a hidden sector contains several metastable hidden glueballs. In this work we shall extend earlier results on hidden valleys to include couplings of the messengers to the standard model Higgs sector. The effective interactions at one-loop couple the hidden gluons to the standard model particles through the Higgs sector. These couplings in turn induce hidden glueball decays to fermion pairs, or cascade decays with multiple Higgs emission. The presence of effective operators of different mass dimensions, often competing with each other, together with a great diversity of states, leads to a great variability in the lifetimes and decay modes of the hidden glueballs. We find that most of the operators considered in this paper are not heavily constrained by precision electroweak physics, therefore leaving plenty of room in the parameter space to be explored by the future experiments at the LHC.