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<sup>-1</sup> (20.3 fb<sup>-1</sup>) 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. Within the constraints of such a scenario, the results presented in this Letter provide the strongest available limits for low-mass dark matter candidates. 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.
|Titolo:||Search for invisible decays of a Higgs boson produced in association with a Z boson in ATLAS|
|Autori interni:||ROSSI, Elvira|
CONVENTI, Francesco Alessandro
DI DONATO, CAMILLA
|Data di pubblicazione:||2014|
|Rivista:||PHYSICAL REVIEW LETTERS|
|Appare nelle tipologie:||1.1 Articolo in rivista|