Search for charged Higgs boson in ttbar in pp collisions at TeV

Main Results

The large top quark production cross section at the Large Hadron Collider offers the opportunity to search for the charged Higgs boson as the decay can be large in extensions of the standard model, if the mass is lighter than the top quark mass. A direct search for the charged Higgs boson in events with one lepton (electron or muon), at least two jets, missing transverse energy, and one hadronically decaying tau lepton has been performed in 36 pb of data collected in proton-proton collisions at TeV. We do not find a signal in our search and derive an upper limit on the branching ratio for masses between 80 and 140GeV/, when assuming .

Figures and Tables from CMS-HIG-11-002

Figure	Label	Description
	Figure 2, left	Jet multiplicity distribution ( GeV/c, ) after requiring one isolated lepton.
	Figure 2, right	MET distribution for events with one isolated lepton and at least two jets; the hatched area shows the uncertainty. The last bin includes the events in the overflow bins.
	Figure 3	Data and MC event yields at various levels of the selection.
	Figure 4, left	Inclusive jet distribution for jet events after the MET cut, and with at least two jets with 30 GeV/c and at least one jet with 20 GeV/c. Entries in the last bin include the overflows.
	Figure 4, right	Probability that a jet fakes a -jet as obtained from the QCD multi-jet events taken during runs with and without pileup.
	Figure 5	Expected number of events after the final event selection as a function of the branching ratio for =120 GeV/. Expectations are also shown separately for WH, HH and (WW) contributions.
	Figure 6	The relation between and the upper limit on for the observed and the expected limit with error band shown in yellow color for =120~GeV/c, where is assumed.
	Figure 7	Upper limit on assuming as a function of . The yellow band shows the band around the expected limit.
	Table 1	The systematics uncertainties for backgrounds, signal events from (HH) and (WH) processes at . These systematic uncertainties are given as the input for the exclusion limit calculation.
	Table 2	Number of expected events for the backgrounds, signal events from (HH) and (WH) processes at =120 GeV/, and the number of observed events after the final event selection. Statistical and systematic uncertainties are shown. The statistical uncertainties are due to MC statistics, while for the $\tau$-fakes the statistical uncertainties are due to the fake rate in the data. Of the 40 events found in the data, 16~(24) events are in the () final state, which is expected as the electron efficiency is lower than the muon efficiency.

-- MicheleGallinaro - 14-Mar-2011