Determination of α_1tns [alpha-s] via the differential 2-jet-rate with ATLAS at LHC [Elektronische Ressource] / vorgelegt von Markus Lichtnecker

aDetermination of via the Differential 2-Jet-Rateswith ATLAS at LHCDissertation der Fakulta¨t fu¨r Physikder¨ ¨Ludwig-Maximilians-Universitat Munchenvorgelegt vonMarkus Lichtneckergeboren in PfarrkirchenMu¨nchen, den 20.04.2011Erstgutachter: Prof. Dr. Otmar BiebelZweitgutachter: Prof. Dr. Wolfgang Du¨nnweberTag der mu¨ndlichen Pru¨fung: 09.06.2011It’s just like flying a spaceship.You push some buttons and see what happens.Zapp Brannigan (FUTURAMA)Have you tried turning it off and on again?Roy Trenneman (The IT Crowd)aaaAbstractThe first determination of the strong coupling constant via the differential 2-jet-rate in pps R1collisions at the LHC (at a center-of-mass-energy of 7 TeV) is presented. Data ( L dt = 700 nb )gathered by the ATLAS experiment are fitted by next-to-leading order (NLO) perturbative QCDpredictions from calculations with the program NLOJET++. As an observable, the jet-flip-parameterfrom 3 to 2 reconstructed jets is investigated, using the infrared and collinear safe k jet algorithm inTthe exclusive reconstruction mode. The jet-flip-parameters from real data are compared to simulateddata from Monte Carlo generators.For the determination of , real data have been corrected for the jet-energy-scale, whereas thescalculations from NLOJET++ have been corrected for the influence of hadronization effects as wellas the impact of the Underlying Event by applying bin-by-bin corrections.