Jonathan HaysSearches with Leptons at the Tevatron Searches for New Physics With Leptons at the Tevatron Jonathan Hays Imperial College London On behalf of the CDF and D0 Collaborations 1

Jonathan HaysSearches with Leptons at the Tevatron Overview Neutralinos and Charginos Stops New resonances W ’, Z ’, and Gravitons Heavy or composite fermions Leptons – clear signatures at hadron colliders -> triggers and event selection 2

Jonathan HaysSearches with Leptons at the Tevatron Neutralinos and Charginos SUSY – squarks and gluinos typically heavy Barger et al., hep-ph/ Spectacular 3 lepton signature Low cross section Leptons can be soft “Golden signature” Direct EWK production – jet free 3

Jonathan HaysSearches with Leptons at the Tevatron Trileptons PLB 680, 24 (2009) Final states with 3 leptons eel,  l, e  l,  l/  Optimised for 2 mSUGRA reference models SUSY1DataBgdSig Eff /%  l 41.2±0.22.8±0.1 eel21.8±0.22.1±0.1 elel 20.8±0.21.3±0.1 SUSY2  l 42.0±0.35.0±0.1 eel00.8±0.13.6±0.1 elel 00.5±0.12.1±0.1 tau  l 00.8±0.11.2±0.1  10.8±0.11.3±0.1 4

Jonathan HaysSearches with Leptons at the Tevatron Trileptons PRL101:251801,2008 CDF-Note 9817 Similar analysis at CDF Classify events according to lepton quality DataBackgroundSignal trilepton11.47 ± ± 0.68 Dilepton+track69.38 ± ±

Jonathan HaysSearches with Leptons at the Tevatron Trileptons Interpret results in mSUGRA No significant excesses observed 6

Jonathan HaysSearches with Leptons at the Tevatron Stop Searches Stop potentially lighter than top Assume chargino heavy sneutrino LSP eµ+(bb)+MET signature Assume chargino light neutralino LSP Look for stop mimicking top production tb±1b01l±tb±1b01l±   l + l - +jets>1 +MET signature With and without b-tags 7 D0-Note 5937 arXiv:

Jonathan HaysSearches with Leptons at the Tevatron Stop Searches 8 SM TotalData b-tagged56.4 ± No-tags65.9 ± < m stop < 135 Excluded at 95%CL

Jonathan HaysSearches with Leptons at the Tevatron Stop Searches 9 BackgroundDataSignal (soft)Signal (hard) SignalM stop / GeVM sneutrino / GeV Soft11080 Hard15050 Set limits using 2D bins S T (leptons + MET) vs H T (jets)

Jonathan HaysSearches with Leptons at the Tevatron RS Gravitons 10 D0 Preliminary e + e - and  final states Warped extra dimensions Predicts KK-gravitons Lightest M 1 ~ TeV avoids fine-tuning Dominant backgrounds Drell Yan and SM 

Jonathan HaysSearches with Leptons at the Tevatron RS Gravitons 11 No significant excess observed D0 Preliminary M 1 > 440  1040 GeV k/M Pl 0.01  0.1

Jonathan HaysSearches with Leptons at the Tevatron Diboson Resonances 12 Search in WW and WZ final states Optimise ET cuts for G, W’, Z’ e + MET + 2(3) jets GravitonZ’W’ Expected exclusion< 632 GeV257 – 630 GeV381 – 420 GeV Observed exclusion< 606 GeV247 – 545 GeV284 – 515 GeV CDF-Note 9730

Jonathan HaysSearches with Leptons at the Tevatron Diboson Resonances 13 W’ decaying into WZ Predicted in many theories 3 leptons + MET No evidence of resonant WZ production Exclude 188 < M W’ < 520 (SSM) 208 < M  T < 408 (LSTC) PRL 104, (2010)

Jonathan HaysSearches with Leptons at the Tevatron Heavy Fermions Search for 4 th gen b’ or composite B and T 5/3 Q  tW, t  bW + ± l ± l ± +bj+MET Data: 2 events, Bgd: 1.6 ± 1.4 M b’,M B > 338 GeV M T 5/3 > 365 GeV 14 arXiv: Submitted to PRL

Jonathan HaysSearches with Leptons at the Tevatron Just a sampling of NP Searches at Tevatron LHC era approaches rapidly! However – Tevatron still has work to do Potential for discovery still there 15