1. 1 introduction sample: W’  tb  Wbb  eνbb/μνbb generator: PYTHIA five samples with W’ mass: 300GeV, 500GeV, 1000GeV, 1500GeV, 2000GeV number of events per sample: 20000 (~10000 for e channel, ~10000 for mu)

2. 2 M T of lepton, MET and 2 jets electron channel muon channel Possible backgrounds: tt-bar single top W+jets Z+jets WW+WZ (ZZ is negligible) QCD (tough task, thinking...) the background samples used here are officially generated by ATLAS Luminosity: 35 fb -1

3. 3 backup

4. 4 Event selections Electron channel at least 1 electron object quality cut cluster E T > 20GeV author: 1 or 3 isEM Robust Medium η cut: 0 < |η| < 1.37, 1.52 < |η| < 2.47 Muon channel at least 1 muon z0 < 10mm |η| < 2.4 reconstructed by combining tracks in the muon spectrometer and inner detector P T > 20GeV (|P T,ID – P T,MS |/P T,ID ) < 0.5 author: 6 tracker hits requirement ptCone20ratio < 0.1 missing E T missing E T cleaning to reject “bad” MET missing E T adjusted for muon events W electron event required a tight electron MET > 25GeV transverse mass of W > 40GeV at least 2 jets cone size ΔR=0.4 P T > 20GeV, |η| < 4.5 isGood remove jets that overlap with leptons at least 1 btag (sv0 > 5.85)