1. b-tag exercise sample: the first 4 root files from ttbar MC sample “group10.phys- sm.mc09_7TeV.105200.T1_McAtNlo_Jimmy.recon.ESD.e510_s765_s767_r13 02.WZphys.100612.07.D3PD” require b-tag variable “tag_sv0_w” > 5.72 number of jets before b-taggingnumber of jets after b-tagging tag_sv0_w

2. b-tag exercise number of events vs. number of b-tagged jets in each passing event

3. qq-bar  W’  bt  bbW  bblv W’ very heavy W’ has momentum tends to zero at lab frame b and t travels in the opposite direction the two b’s likely to travel at a roughly opposite direction

4. also… revising the write-up of my QCD background study learning how to generate W’ sample by PYTHIA several steps (and days) are required to generate the sample what to do in the coming few days: tonight: finish revising the write-up tomorrow and later: generate the samples and write my code