Precision Measurements of the Top Quark Mass at CDF Un-ki Yang Manchester Christmas Meeting, Dec 20-21, 2006 Un-ki Yang Manchester Christmas Meeting, Dec 20-21, 2006 Great Performance Delivered ~2.0 fb -1 Peak Inst. Lum ~2.5E32 cm -2 s -1 Summer 2005 M top ~ 2.9 GeV Run I M top ~ 4.3 GeV Spring 2006 M top ~2.3 GeV Summer 2006 M top ~ 2.1 GeV 74% weight by CDF (D0: ~350pb-1) Very Productive Year for CDF Top Mass group under my co-leadership Template Method in lepton+jet Samples High-pt central leptons (e,mu), 4 jets and a large missing Et 2 kinematic fitter: fully reco. ttbar system Samples High-pt central leptons (e,mu), 4 jets and a large missing Et 2 kinematic fitter: fully reco. ttbar system Reconstruct m t that fits event best over all comb. (m W =80.4 GeV, ) Create templates for various input Mtop & bkgds. Maximum Likelihood fit using signal+bkgd templates W+W+ W-W- t t b-jet jet l Results in the Lepton+Jet Channel Mtop and JES : by likelihood fit using shape comparisons of m t & m jj dist. World best measurement (Spring06) 40% improvement on JES using Wjj PRD/PRL with 320 pb -1 Toward 2nd publication with 1.5 fb -1 by early next summer CDF and Tevatron Summary Many measurements in all the different channels consistency Different methods of extraction with different sensitivity confidence Combine all channels and all methods precision Many measurements in all the different channels consistency Different methods of extraction with different sensitivity confidence Combine all channels and all methods precision Tevatron Mass and Impact hep-ex/ (summer 06) EWK Fit: Mtop