Constraints on simplified dark matter models involving an $s$-channel mediator with the ATLAS detector in $pp$ collisions at $\sqrt{s} = 13$ TeV

TL;DR

This paper summarizes ATLAS collider search results for fermionic dark matter models with an s-channel mediator, setting limits on mediator properties using 13 TeV proton-proton collision data from LHC Run 2.

Contribution

It provides the first comprehensive interpretation of ATLAS search results within simplified dark matter models involving various s-channel mediators.

Findings

Excluded mediator masses up to several TeV

Set limits on mediator couplings and masses

Constrained parameter space of simplified dark matter models

Abstract

This paper reports a summary of searches for a fermionic dark matter candidate in the context of theoretical models characterised by a mediator particle exchange in the $s$-channel. The data sample considered consists of $pp$ collisions delivered by the Large Hadron Collider during its Run 2 at a centre-of-mass energy of $\sqrt{s} = 13$ TeV and recorded by the ATLAS detector, corresponding to up to 140 $fb^{-1}$. The interpretations of the results are based on simplified models where the new mediator particles can be spin-0, with scalar or pseudo-scalar couplings to fermions, or spin-1, with vector or axial-vector couplings to fermions. Exclusion limits are obtained from various searches characterised by final states with resonant production of Standard Model particles, or production of Standard Model particles in association with large missing transverse momentum.