Speaker
Ms
Silje Hattrem Raddum
(University of Oslo)
Description
Based on 1.03 fb-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector, upper limits on the branching ratio of top decaying to a bottom and a charged Higgs were extracted by performing a profile likelihood statistical analysis. Using the single- and di-lepton channels with leptonically decaying tau(s) in the final state, we found that data agree well with the Standard Model expectation. Assuming B(H+ -> tau nu) = 1, the upper limits on the branching fraction B(t -> bH+) were found to be between 5.2% and 14.1% for H+ masses in the range 90 GeV to 160 GeV. Previous measurements of the ttbar cross sections have usually been made under the assumption that the top decays exclusively to a bottom and a W boson, but this analysis can obviously not rely on such an assumption. Thus, a control region was used to estimate the ttbar cross section. However, one can not simply neglect a small, but potential signal contamination in the control region. In order to account for a potential signal contamination, the control region was implemented in the likelihood function as a counting experiment.
Primary author
Ms
Silje Hattrem Raddum
(University of Oslo)
