51ÁÔÆæÈë¿Ú

Abstract:

Motivated by the recent interest in light weakly interacting massive particles (WIMPs) of mass ∼O(10GeV/c2), an extension of the elastic, spin-independent, WIMP-nucleon cross-section limits resulting from the CRESST-II commissioning run (2007) are presented. Previously, these data were used to set cross-section limits from 1000GeV/c2 down to ∼17GeV/c2, using tungsten recoils, in 47.9 kg-days of exposure of calcium tungstate. Here, the overlap of the oxygen and calcium bands with the acceptance region of the commissioning run data set is reconstructed using previously published quenching factors. The resulting elastic WIMP cross-section limits, accounting for the additional exposure of oxygen and calcium, are presented down to 5GeV/c2. © 2012 American Physical Society.

Abstract:

A search for a heavy Standard Model Higgs boson decaying via H→ZZ→ℓ+ℓ-qq̄, where ℓ=e, μ, is presented. The search is performed using a data set of pp collisions at √s=7 TeV, corresponding to an integrated luminosity of 1.04 fb-1 collected in 2011 by the ATLAS detector at the CERN LHC collider. No significant excess of events above the estimated background is found. Upper limits at 95% confidence level on the production cross section (relative to that expected from the Standard Model) of a Higgs boson with a mass in the range between 200 and 600 GeV are derived. Within this mass range, there is at present insufficient sensitivity to exclude a Standard Model Higgs boson. For a Higgs boson with a mass of 360 GeV, where the sensitivity is maximal, the observed and expected cross section upper limits are factors of 1.7 and 2.7, respectively, larger than the Standard Model prediction. © 2011 CERN.