# Probing the Pseudoscalar portal to Dark Matter via $\bar{b} b Z( \rightarrow \ell\ell) + E_{T} \hspace{-8mm}/\hspace{4mm}$: From the LHC to the Galactic Centre Excess

## TL;DR

This paper introduces a novel LHC search strategy for Dark Matter involving a pseudoscalar portal, which can explore new parameter space and potentially explain the Galactic Centre gamma-ray excess.

## Contribution

It proposes a new collider search channel for Dark Matter via a pseudoscalar portal, extending the reach beyond existing methods and linking collider results to astrophysical observations.

## Key findings

- The proposed search can probe previously inaccessible parameter space.
- It offers a method to test the Dark Matter origin of the Galactic Centre excess.
- The search is effective with LHC Run 2 data.

## Abstract

We propose a new search for Dark Matter at the LHC, characteristic of scenarios beyond the Standard Model with a pseudoscalar portal between the visible and dark sectors. This search, leading to a $\bar{b} b Z( \rightarrow \ell\ell) + E_{T} \hspace{-4mm}/\hspace{2mm}$ final state, reaches large regions of parameter space not probed by Dark Matter searches via multi-jet $+ E_{T} \hspace{-4mm}/\hspace{2mm}$, searches for new scalars and flavour bounds. We show that this search could be used to test the Dark Matter origin of the gamma ray Galactic Centre excess with LHC Run 2 data.