Invisible Higgs in weak bosons associative production with heavy quarks at LHC: probing mass and width

Abstract

New physics coupled to the Higgs boson may hide it in the standard decay channels to be investigated at LHC. We consider the models where new invisible dominant decay modes of the Higgs boson are responsible for this hiding. We propose to study at LHC the weak boson production associated with heavy quarks: our analysis revealed that boson pair invariant mass distribution is sensitive to both mass and width of the invisible Higgs boson, if it is not too far from the weak boson pair threshold. We present tree-level results for the most relevant cases of top quarks and of bottom quarks in Standard Model extensions with large $b$-quark Yukawa coupling. We argue that QCD corrections do not spoil these results allowing for unambiguous extraction of the Higgs boson mass and width from the analysis of large enough amount of data.Comment: 26 pages, 14 figures, references adde