2015:groups:tools:backgrounds
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2015:groups:tools:backgrounds [2015/06/03 17:42] jonathan.butterworth |
2015:groups:tools:backgrounds [2015/07/06 12:09] philippe.gras Moved to e-group mailing list |
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| ====== A quick study on the impact of irreducible-background subtraction ====== | ====== A quick study on the impact of irreducible-background subtraction ====== | ||
| + | //If you are interested in contributing please subscribe to the [[https://e-groups.cern.ch/e-groups/EgroupsSearch.do?searchValue=houches-2015-topics-tools-bgnd-subtraction|mailing list]].// | ||
| - | + | Jon Butterworth, Vitaliano Ciulli, Paolo Francavilla, Frank Krauss, Carlo Pandini, Luca Parrozzi, ... | |
| - | Jon Butterworth, Paolo Francavilla, Frank Krauss, Carlo Pandini, Luca Parrozzi, ... | + | |
| github repository: https://github.com/perrozzi/leshouches_bkgsub | github repository: https://github.com/perrozzi/leshouches_bkgsub | ||
| Line 14: | Line 14: | ||
| 14 TeV (maybe also 13 TeV), B-tag up to y=2.5 (allowing a veto on b-jets in this region if it helps). Also look at the impact of pseudo-top vetos. | 14 TeV (maybe also 13 TeV), B-tag up to y=2.5 (allowing a veto on b-jets in this region if it helps). Also look at the impact of pseudo-top vetos. | ||
| - | Double leptonic channel: | + | Double leptonic channel (eμ only): |
| 1. Consider WWjj as the signal. Look at WW scattering-like WWjj topologies. Study the contribution to the signal coming from double-resonant (DR), single-resonant (SR) and continuum (C) ttbar processes, and the sum. | 1. Consider WWjj as the signal. Look at WW scattering-like WWjj topologies. Study the contribution to the signal coming from double-resonant (DR), single-resonant (SR) and continuum (C) ttbar processes, and the sum. | ||
| Line 21: | Line 21: | ||
| The ATLAS paper is here: https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-01/ | The ATLAS paper is here: https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-01/ | ||
| The cuts which define the fiducial phase space are: | The cuts which define the fiducial phase space are: | ||
| - | * lepton pT > 20 GeV (muon or electron), leading lepton pT > 25 GeV | + | * pT μ > 20 GeV (muon or electron), leading lepton pT > 25 GeV |
| * muon |η| < 2.4, electron |η| < 1.37 or 1.52 < |η| < 2.47, | * muon |η| < 2.4, electron |η| < 1.37 or 1.52 < |η| < 2.47, | ||
| * no jets with p > 25 GeV, rapidity |y| < 4.5 and separated from an electron by ∆R > 0.3 | * no jets with p > 25 GeV, rapidity |y| < 4.5 and separated from an electron by ∆R > 0.3 | ||
| - | * | + | * pT (ll') > 30 GeV |
| + | * m(ll′) > 10 GeV, pT,Rel > 25 GeV | ||
| + | I (Jon) suggest we simplify this to something like: | ||
| + | * pT leptons all > 25 GeV | ||
| + | * |η| leptons all < 2.4 | ||
| + | * m(ll′) > 10 GeV | ||
| + | * count the jets, and b-jets, with p > 25 GeV, rapidity |y| < 4.5 | ||
| + | |||
| + | ... but I haven't check the CMS paper yet. | ||
| 3. Consider WWbb as the signal, motivated by WWH (H->bb). Same study (DR/SR/C/Sum). | 3. Consider WWbb as the signal, motivated by WWH (H->bb). Same study (DR/SR/C/Sum). | ||
| + | For HH->WWbb, a possible proposal could be: | ||
| + | |||
| + | Objects Definition: | ||
| + | * electrons and muons: pT > 25 GeV; |eta| < 2.4 | ||
| + | * jets: pT > 25 GeV; | eta | <4.5 | ||
| + | * bjets: jets with | eta |< 2.5 and b-labelled | ||
| + | |||
| + | NOTE 1: in the ATLAS WW analysis, the jets are build from all the particles, excluding muons and neutrinos. | ||
| + | If we adopt this definition, we will need to run an Overlap Removal between electrons and jets, to avoid counting jets which are in fact electrons. | ||
| + | NOTE 2: The ATLAS WW analysis is vetoing events if (among the other selections) : | ||
| + | * there are jet (and b-jet), or | ||
| + | * there are extra leptons. | ||
| + | If we want to extend to events with b-jets, we should consider how to handle the semi-leptonic b-decays in jets ()to avoid to veto the event because of the leptons in jets. | ||
| + | |||
| + | Event Selection: | ||
| + | fill()CutFlow | ||
| + | * 2 opposite charged leptons | ||
| + | * 1 muon, 1 electron | ||
| + | fill(CutFlow) | ||
| + | fill(MET_rel) | ||
| + | * MET_rel>25 GeV, | ||
| + | fill(CutFlow) | ||
| + | fill(mll) | ||
| + | * mll>10 GeV, | ||
| + | fill(CutFlow) | ||
| + | fill(b-jets, jets) #b-jets VS #jets | ||
| + | fill(jets), pt, eta | ||
| + | * 2+ bjets | ||
| + | fill(CutFlow) | ||
| + | fill(bjet 1) pt, eta | ||
| + | fill(bjet 2) pt, eta | ||
| + | fill(electron) pt, eta | ||
| + | fill(muon) pt, eta | ||
| + | fill(MET) | ||
| + | fill(mT(MET,e,mu)) | ||
| + | * 100<mT(MET,e,mu)/GeV<150 | ||
| + | fill(CutFlow) | ||
| + | fill(electron) pt, eta | ||
| + | fill(muon) pt, eta | ||
| + | fill(b-jet1) pt, eta | ||
| + | fill(b-jet2) pt, eta | ||
| + | fill(m(bb)) | ||
| + | * 100<m(bb)/GeV<150 | ||
| + | fill(CutFlow) | ||
| + | fill(b-jets, jets) #b-jets VS #jets | ||
| + | fill(jets), pt, eta | ||
| + | |||
| + | |||
| + | NOTE: it would be nice to use some top veto. | ||
| + | the pseudo-top definition could be a nice idea, but it is defined | ||
| + | in a straightforward way for the Semi-leptonic channel. | ||
| + | One can test the b-lepton mass (associating the b to the closer lepton). | ||
| + | |||
| Semi-leptonic channel: | Semi-leptonic channel: | ||
| 4. Consider ttbar as signal. Look at distortion in b-lepton mass from SR/C/Sum/WWbb-non-top contributions. | 4. Consider ttbar as signal. Look at distortion in b-lepton mass from SR/C/Sum/WWbb-non-top contributions. | ||
| - | |||
| ==== Wb versus t ==== | ==== Wb versus t ==== | ||
2015/groups/tools/backgrounds.txt · Last modified: 2015/07/14 08:31 by philippe.gras
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