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 fb−1 at a centre-ofmass
energy of 7 TeV and 19.4 fb−1 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.