Search for heavy resonances decaying to a $W$ or $Z$ boson and a Higgs boson in the $q\bar{q}^{(\prime)}b\bar{b}$ 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 a W or Z boson and a Higgs boson in proton-proton collisions at 13 TeV, using ATLAS data, finding no significant deviation from the Standard Model but setting limits on possible new particles.

Contribution

First search for heavy vector triplet resonances decaying to W/Z and Higgs bosons in the $q\bar{q}^{(\prime)}b\bar{b}$ final state at 13 TeV with ATLAS, providing new constraints on such models.

Findings

No significant excess observed; largest local significance is 3.3 sigma.

Set upper limits on production cross-section times branching ratio between 1.1 and 3.8 TeV.

Established constraints on simplified models with heavy vector triplets.

Abstract

A search for heavy resonances decaying to a $W$ or $Z$ boson and a Higgs boson in the $q\bar{q}^{(\prime)}b\bar{b}$ final state is described. The search uses 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} =$ 13 TeV collected by the ATLAS detector at the CERN Large Hadron Collider in 2015 and 2016. The data are in agreement with the Standard Model expectations, with the largest excess found at a resonance mass of 3.0 TeV with a local (global) significance of 3.3 (2.1) $\sigma$. The results are presented in terms of constraints on a simplified model with a heavy vector triplet. Upper limits are set on the production cross-section times branching ratio for resonances decaying to a $W$ ($Z$) boson and a Higgs boson, itself decaying to $b\bar{b}$, in the mass range between 1.1 and 3.8 TeV; the limits range between 83 and 1.6 fb (77 and 1.1 fb) at 95% confidence level.