J. Huston lepton + jets 7/15/05 A short theory introduction to asymmetry in t-tbar production … ongoing work with D. Amidei and T. Schwarz J. Huston Michigan State University

J. Huston lepton + jets 7/15/05 Top production at the Tevatron effect not present in LO MC’s use MCFM to study at parton level most complete treatment in paper by Kuhn and Rodrigo

J. Huston lepton + jets 7/15/05 Properties of t-tbar events All MCFM plots will show the cross section in fb MCFM final state consists of a t, a tbar and (maybe) 1 jet p T is ttbar p T

J. Huston lepton + jets 7/15/05 Asymmetry

J. Huston lepton + jets 7/15/05 Asymmetry

J. Huston lepton + jets 7/15/05 Dependence on t-tbar p T

J. Huston lepton + jets 7/15/05 p T j > 10 GeV/c

J. Huston lepton + jets 7/15/05 Summary of asymmetries

J. Huston lepton + jets 7/15/05 Scale dependence of asymmetry …either puzzling or profound?

J. Huston lepton + jets 7/15/05 Next steps More studies cross-checks with MCFM  t-tbar + 1 jet at NLO complete later this summer; useful for looking at high p T asymmetry  synergy with ttbar + jet study  I’ve been talking with the authors Continue studies with samples  effects of soft gluon radiation on asymmetry  ability to tag hard/soft t-tbar production  feedback for optimizing analysis procedure/cuts on the data