https://doi.org/10.1140/epjc/s2003-01251-0
theoretical physics
Prospects for observing an invisibly decaying Higgs boson in the ${t \bar t H}$ production at the LHC
1
Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia
2
Jozef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
3
Institute of Computer Science, University of Mining and Metallurgy, al. A. Mickiewicza 30, 30-059, Poland
4
Institute of Computer Science, Jagellonian University, ul. Nawojki 11, 30-072, Krakow, Poland
5
Institute of Computer Science, Institute of Nuclear Physics, ul. Radzikowskiego 152, 31-342, Krakow, Poland
The prospects for observing an invisibly decaying Higgs boson in the ${t \bar t H}$ production at LHC are discussed. An isolated lepton, reconstructed hadronic top-quark decay, two identified b-jets and a large missing transverse energy are proposed as the final state signature for event selection. Only the standard model backgrounds are taken into account. It is shown that the $t\bar t Z$, $t \bar t W$, $b \bar b Z$ and $b \bar b W$ backgrounds can individually be suppressed below the signal expectation. The dominant source of background remains the $t \bar t$ production. The key for the observability will be an experimental selection which allows further suppression to be achieved of the contributions from the $t \bar t$ events with one of the top quarks decaying into a tau lepton. Depending on the details of the final analysis, an excess of the signal events above the standard model background of about 10% to 100% can be achieved in the mass range m H = 100-200 GeV.
© Springer-Verlag, 2003
