The sensitivity of the Higgs boson branching ratios to the W boson width

Abstract

The Higgs boson branching ratio into vector bosons is sensitive to the decay widths of those vector bosons because they are produced with at least one boson significantly off-shell. Γ(H→VV) is approximately proportional to the product of the Higgs boson coupling and the vector boson width. ΓZ is well measured, but ΓW gives an uncertainty on Γ(H→WW) which is not negligible. The ratio of branching ratios, BR(H→WW)/BR(H→ZZ) measured by a combination of ATLAS and CMS at LHC is used herein to extract a width for the W boson of ΓW=1.8−0.3+0.4 GeV by assuming Standard Model couplings of the Higgs bosons. This dependence of the branching ratio on ΓW is not discussed in most Higgs boson coupling analyses.