Presentation on theme: "Skeleton outline for the physics case document M. Shochet December 15, 2005."— Presentation transcript:
Skeleton outline for the physics case document M. Shochet December 15, 2005
Physics Case for the FTK Fast Track Finder I.Introduction The general argument: unknown new physics best toolbox Importance of the 3 rd generation to new physics: EWK symmetry breaking, SUSY, … Challenge of efficiency, rapid identification of b and jets in the trigger because of large backgrounds oEarly access to high quality tracks can give rapid rejection in L2 lower deadtime can reduce the L1 threshold to increase physics efficiency Rapid tracking can be useful for many purposes including calibration: ex, single isolated track trigger for calorimeter calibration (low P T & W→ ) Here we focus on 3 rd generation partons Remaining sections:
–b-jet ID – -jet ID (1 & 3 prong) –Z→bb –bbH/A→ 4 b’s (& 2 b’s 2 ’s ?) –VBF production of H→ –H→hh→4b’s –B s → –(generic l triggers ?) –Summary & conclusions * As we go, we have to keep tabs on the total requested additional L1 jet trigger rate (use common thresholds when possible).
II.The CDF Experience ex: early predicted trigger rates vs. reality; SVT success – B physics expectation before run I vs. what was done (SVT needed for unanticipated physics); Z bb – bb purity after trigger III.Overview of FTK (technical details elsewhere) IV.Rapid selection of b-jets Simulation samples used Optimization procedure b-jet efficiency vs light quark & gluon rejection factor Comparison with planned trigger and offline algorithms IV.Rapid selection of jets Same bullets as in III with addition of –Triggering on 3-prong decay (for polarization information) V.Z→bb Measure b-jet response of ATLAS calorimeter, check the shift when b semileptonic decay is identified, additional check of overall ATLAS jet energy scale Problem: maintaining low enough L1 rate and having low M JJ turn- on to get background shape
Solution: high P T Z’s (3-jet trigger) Background & signal after trigger Z mass uncertainty & width vs. integrated luminosity VI.bbH/A→4 b’s pick a few points in parameter space (just) outside ATLAS sensitivity region Signal & background samples used (describe use of ATLFast and use of transfer functions) Background rate & signal efficiency vs selection criteria Observation significance vs integrated luminosity & comparison to ATLAS baseline result VII.VBF production of H Same as above, with discussion of forward jets &/or rapidity gaps.