摘要 :
A search for a heavy neutral resonance X is performed in the X→WW→evμv decay channel using pp collision data corresponding to an integrated luminosity of36.1fb-1,collected at a centre-of-mass energy of13TeV by the ATLAS detecto...
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A search for a heavy neutral resonance X is performed in the X→WW→evμv decay channel using pp collision data corresponding to an integrated luminosity of36.1fb-1,collected at a centre-of-mass energy of13TeV by the ATLAS detector at the Large Hadron Collider.The resonance can be either a heavy scalar Higgs boson or other heavy resonances with different spins.Two scenarios are considered for the heavy Higgs boson hypothesis with different decay widths in both the gluon-gluon fusion and the vector-boson fusion production modes,namely a narrow-width approximation and a large width assumption.Several hypotheses are used for the interpretation to search for other resonances,like two Higgs doublet models,Georgi-Machacek model,heavy vector triplet model in the quark-antiquark annihilation mode,a bulk Randall-Sundrum graviton model with a spin-2Graviton with a curvature scale parameter k/(M)Pl of either1or0.5and a spin-2signal in the vector-boson fusion mode.Three orthogonal event categories are defined in the analysis:two vector-boson fusion categories which are optimised for the signals produced in the vector-boson fusion mode with one jet or at least two jets and one quasi-inclusive gluon-gluon fusion category where the vector-boson fusion phase spaces defined by the two vector-boson fusion categories are excluded.No significant excess of events beyond the Standard Model background prediction is found in the mass range between200GeV and up to5TeV.Upper limits are set on the product of the production cross section of the resonance and the X→WW branching fraction.For heavy Higgs boson signals,values above6.4pb and1.3pb at mH=200GeV and above0.008pb and0.005pb at4TeV are excluded at95％confidence level for the gluon-gluon fusion and the vector-boson fusion production modes,respectively.For signals predicted by the heavy vector triplet model,mass values below1.3TeV are excluded.Similarly,for signals predicted by the bulk Randall-Sundrum graviton model,mass values below1.1TeV and850GeV are excluded for k/(M)Pl=1and k/(M)Pl=0.5,respectively.
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