Search for a High Mass Higgs Boson in the Channel H - ZZ - llbb and digital filtering for the ATLAS level-1 calorimeter trigger

[摘要] The Standard Model of particle physics predicts the existence of a new massive state: the Higgs Boson. The discovery or exclusion of this particle is one of the main goals of the ATLAS experiment. One of the greatest experimental challenges at the LHC is to achieve efficient triggering. The ATLAS rst level calorimeter trigger uses reduced granularity information from the calorimeters to search for high ET e, y,t and jets as well as identifying high Emiss T and total ET events. A Finite Impulse Response (FIR) lter combined with a peak nder is applied to identify signals, determine their correct bunch-crossing and improve the energy measurement. A study to determine the optimum lter coecients is presented. The performance of these lters is investigated with commissioning data and cross-checks of the calibration with initial beam data are shown. In this thesis a study of the search sensitivity in the channel H - ZZ - llbb is presented. This channel can contribute to the Higgs search in the high mass region that has been unexplored by previous lower energy colliders. The dominant backgrounds, without b-tagging applied, are extracted from 34:6 pb

[发布机构] University:University of Birmingham;Department:School of Physics and Astronomy

[关键词] Q Science;QC Physics