Search for invisible decays of a Higgs boson produced in association with a Z boson in ATLAS

ATLAS COLLABORATION, G. AAD, M.T. DOVA ET AL

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2014

0031-9007

A search for evidence of invisible-particle decay modes of a Higgs boson produced in association with a Z boson at the Large Hadron Collider is presented. No deviation from the Standard Model expectation is observed in 4.5 fb−1 (20.3 fb−1) of 7 (8) TeV pp collision data collected by the ATLAS experiment. Assuming the Standard Model rate for ZH production, an upper limit of 75%, at the 95% confidence level is set on the branching ratio to invisible-particle decay modes of the Higgs boson at a mass of 125.5 GeV. The limit on the branching ratio is also interpreted in terms of an upper limit on the allowed dark matter?nucleon scattering cross section within a Higgs-portal dark matter scenario. Limits are also set on an additional neutral Higgs boson, in the mass range 110 < mH < 400 GeV, produced in association with a Z boson and decaying to invisible particles.