Top-antitop cross section measurement as a function of the jet multiplicity in the final state and beyond the Standard Model top-antitop resonances search at the ATLAS detector at CERN

QC Physics

Ferreira de Lima, Danilo Enoque ; Buttar, Craig

University:University of Glasgow

Department:School of Physics and Astronomy

关键词: physics,particle physics,top quark,measurement,search,Beyond the Standard Model,topcolor,Kaluza-Klein gluons,Standard Model,unfolding,ATLAS,CERN;   

Others  :  http://theses.gla.ac.uk/5015/1/2014ferreiradelimaphd.pdf

来源: University of Glasgow

【 摘 要 】

The top quark is the heaviest particle in the Standard Model, with a strong coupling to the Higgs boson.It is often seen as a window to new physics, therefore understanding its production is a key ingredientfor testing the Standard Model or physics Beyond the Standard Model. In this document, theproduction cross section of top-antitop pairs in its semileptonic decay channel is measured as a function of thejet multiplicity in the ATLAS experiment, using proton-proton collisions at the center-of-mass energy ofsqrt(s) = 7 TeV.The top-antitop production with extra jets is the main background for many analyses, including the top-antitop-Higgsproduction studies. The analysis performed is extended in a search for Beyond the Standard Model physicswhich predicts a resonance decaying in a top-antitop pair, using ATLAS data at center-of-mass energy ofsqrt(s) = 7 TeV. The latter analysis is repeated for ATLAS data collected with sqrt(s) = 8 TeV.Performance studies of b-tagging algorithms in the ATLAS Trigger System are also presented.