Search for heavy resonances decaying into $WW$ in the $e\nu\mu\nu$ final state in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

TL;DR

This paper reports a search for heavy resonances decaying into WW in the eνμν final state using 13 TeV proton-proton collision data from ATLAS, setting limits on various theoretical models without finding evidence of such particles.

Contribution

First search for heavy WW resonances in the eνμν channel at 13 TeV with ATLAS, providing upper limits across multiple models and production mechanisms.

Findings

No evidence of heavy WW resonances was observed.

Upper limits on production cross-section times branching ratio were set for masses between 200 GeV and 5 TeV.

Constraints were placed on several theoretical models including Higgs-like scalars and extra-dimensional models.

Abstract

A search for neutral heavy resonances is performed in the $WW\to e\nu\mu\nu$ decay channel using $pp$ collision data corresponding to an integrated luminosity of 36.1 fb$^{-1}$, collected at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. No evidence of such heavy resonances is found. In the search for production via the quark--antiquark annihilation or gluon--gluon fusion process, upper limits on $\sigma_X \times B(X \to WW)$ as a function of the resonance mass are obtained in the mass range between 200 GeV and up to 5 TeV for various benchmark models: a Higgs-like scalar in different width scenarios, a two-Higgs-doublet model, a heavy vector triplet model, and a warped extra dimensions model. In the vector-boson fusion process, constraints are also obtained on these resonances, as well as on a Higgs boson in the Georgi--Machacek model and a heavy tensor particle coupling only to gauge bosons.