Search for massive WH resonances decaying into the l nu b anti-b final state at sqrt(s) = 8 TeV

TL;DR

This paper reports a search for heavy W' resonances decaying into a W and Higgs boson in proton-proton collisions at 8 TeV, setting new mass limits and using advanced jet substructure techniques.

Contribution

It introduces a novel analysis method for identifying high-mass W' decays into WH using jet substructure and flavor tagging, improving existing mass exclusion limits.

Findings

Lower W' mass limit of 1.4 TeV in little Higgs models

Lower W' mass limit of 1.5 TeV in heavy vector triplet models

Most restrictive W' decay limit to date at 1.8 TeV

Abstract

A search for a massive resonance W' decaying into a W and a Higgs boson in the l nu b anti-b (l = e, mu) final state is presented. Results are based on data corresponding to an integrated luminosity of 19.7 inverse femtobarns of proton-proton collisions at sqrt(s) = 8 TeV, collected using the CMS detector at the LHC. For a high-mass ( greater than 1 TeV) resonance, the two bottom quarks coming from the Higgs boson decay are reconstructed as a single jet, which can be tagged by placing requirements on its substructure and flavour. Exclusion limits at 95% confidence level are set on the production cross section of a narrow resonance decaying into WH, as a function of its mass. In the context of a little Higgs model, a lower limit on the W' mass of 1.4 TeV is set. In a heavy vector triplet model that mimics the properties of composite Higgs models, a lower limit on the W' mass of 1.5 TeV is set. In the context of this model, the results are combined with related searches to obtain a lower limit on the W' mass of 1.8 TeV, the most restrictive to date for decays to a pair of standard model bosons.