Search for new particles in events with a hadronically decaying W or Z boson and large missing transverse momentum at $\sqrt{s}$ = 13 TeV using the ATLAS detector

TL;DR

This paper reports a search for new particles in proton-proton collisions at 13 TeV with the ATLAS detector, focusing on events with a hadronically decaying W/Z boson and large missing transverse momentum, setting limits on various new physics models.

Contribution

First search at 13 TeV for particles with W/Z bosons decaying hadronically and missing energy, providing model-independent limits and testing multiple new physics scenarios.

Findings

No significant excess over Standard Model expectations.

Set exclusion limits for axion-like particles and dark matter models.

Provided model-independent cross-section limits ranging from 0.3 fb to 79.5 fb.

Abstract

A search is presented for new particles produced in proton-proton collisions at a centre-of-mass energy of 13 TeV that result in final states comprising a massive vector (W or Z) boson that decays hadronically and large missing transverse momentum. The data sample was collected with the ATLAS experiment at the Large Hadron Collider from 2015 to 2018 and corresponds to an integrated luminosity of 140 fb$^{-1}$. No significant excess over the Standard Model expectation is observed. Model-independent 95% confidence-level limits on the visible cross-section that range from 0.3 fb to 79.5 fb are obtained for non-Standard-Model processes. Exclusion limits are also presented for models with axion-like particles, for two-Higgs-doublet models with a pseudo-scalar mediator between the Standard Model and the dark sector, for the invisible decay of the Higgs boson and for pair-produced weakly interacting dark matter candidates.