Search for Higgs boson off-shell production in proton-proton collisions at 7 and 8 TeV and derivation of constraints on its total decay width

TL;DR

This paper searches for off-shell Higgs boson production in proton-proton collisions at 7 and 8 TeV to set constraints on its total decay width, using CMS data and analyzing decay into W+W- pairs.

Contribution

It provides new limits on the Higgs boson's total decay width by analyzing off-shell production in multiple channels with CMS data at different energies.

Findings

Upper limit on off-shell Higgs yield: 2.4 times the SM prediction

Upper limit on total width: 26 MeV (observed)

Combined width limit with ZZ channel: 13 MeV (observed)

Abstract

A search is presented for the Higgs boson off-shell production in gluon fusion and vector boson fusion processes with the Higgs boson decaying into a W+W- pair and the W bosons decaying leptonically. The data observed in this analysis are used to constrain the Higgs boson total decay width. The analysis is based on the data collected by the CMS experiment at the LHC, corresponding to integrated luminosities of 4.9 inverse femtobarns at a centre-of-mass energy of 7 TeV and 19.4 inverse femtobarns at 8 TeV, respectively. An observed (expected) upper limit on the off-shell Higgs boson event yield normalised to the standard model prediction of 2.4 (6.2) is obtained at the 95% CL for the gluon fusion process and of 19.3 (34.4) for the vector boson fusion process. Observed and expected limits on the total width of 26 and 66 MeV are found, respectively, at the 95% confidence level (CL). These limits are combined with the previous result in the ZZ channel leading to observed and expected 95% CL upper limits on the width of 13 and 26 MeV, respectively.