Information
Analysers:
- Janos Karancsi - PhD student (ATOMKI & UNIDEB, Debrecen, HU)
- Viktor veszpremi - PhD (Wigner, Budapest, HU)
- Petar Maksimovic - Prof. PhD (Johns Hopkins University, Baltimore, US)
- Brandon Chiarito - Student (Johns Hopkins University, Baltimore, US)
Links:
For a lot of results we share a common elog with the JHU group:
JHU elog
Twikis:
Useful info:
Papers, Notes:
| Links |
Date |
Author |
Title |
Comment |
| arXiv:physics/0308063 |
2003 |
G. Punzi |
Sensitivity of searches for new signals and its optimization |
| CMS PAS JME-09-001 |
2009 |
CMS |
A Cambridge-Aachen (C-A) based Jet Algorithm for boosted top-jet tagging |
| arXiv:1011.2268 |
2010 |
J. Thaler, K. V. Tilburg |
Identifying Boosted Objects with N-subjettiness |
tau variables (N-sj.), Mistag rates, tagging efficiencies |
| arXiv:1006.2833 |
2010 |
T. Plehn et. al |
Stop Reconstruction with Tagged Tops |
| [[http://arxiv.org/pdf/1007.2221.pdf][]] |
2010 |
K. Rehermann, B. Tweedie |
Efficient Identification of Boosted Semileptonic Top Quarks at the LHC |
Mini Isolation, new default for SUSY group. |
| CMS-PAS-B2G-12-006 (Twiki) |
2013 |
CMS |
Search for Anomalous Top Quark Pair Production in the Boosted All-Hadronic Final State |
Mistag rate of top tagging algo, Multijet bkg estimation |
| CMS-PAS-B2G-12-006 (Twiki) |
2013 |
CMS |
Search for ttbar resonances in semileptonic final state |
2D cut for semi-leptonic top |
| CMS-PAS-JME-13-007 |
2014 february |
CMS |
Boosted Top Jet Tagging at CMS |
|
| SUS-14-007 (Approval) |
2015 |
Razor group |
Search for SUSY with boosted W's using the razor variables |
|
Presentations:
- New MC/Gen Info in 74X - PPD General - June 17, 2015
- Boosted top trigger - AK8PFJet360_TrimMass30 - ,March 26, 2015
- Top Tagging at 13 TeV - JMAR Meeting, March 11, 2015
- Update on Differential tt Cross Section with Boosted Tops - Top Cross Section Meeting, July 24, 2014
- Jet Substructure Hands-on Advanced Tutorial Session - LPC, June 18-19, 2014
- Physics performance and potentials of boosted topologies - CMS Physics week, February 24, 2014
- QCD-Multijet Background Modelling Using The ABCD Method - ttH meeting, February 28, 2013
- Background Estimation Methods (ABCD - slide 8)
Important results
Links to latest results
Object/Event selections
Object definitions
All objects come from
MiniAOD slimmed Pat collections:
MiniAOD objects
Jets
Anti-kt algorithm jets with cone size: R=0.8,
B2G baseline cuts:
- pT > 100 GeV /c
- | eta | < 4
Electrons
gedGsfElectrons with cuts (
B2G baseline: pT > 30
GeV /c, |eta | < 2.5):
- pT > 35 GeV /c
- | eta | < 2.5
Muons
muons with cuts (
B2G baseline: pT > 30
GeV /c, |eta | < 2.5)
- pT > 45 GeV /c
- | eta | < 2.1
- tight ID
MET
type1 PF MET
Event Selection
Exactly 2 AK8 Jets with cuts (loose hadronic top selection):
- pT > 400 GeV /c
- tau3 / tau2 < 0.75
- Pruned Mass > 140 Gev/c^2
Signal selection cuts (See below)
- R (Razor variable) - Recipe
- Calculated for jets with | eta | < 3
- H_T,all = Sum ( AK8Jet pT ) + Sum ( Lepton pT ) + MET
- DPhi = | DeltaPhi ( top_had1, top_had2 ) |
Signal Selection
Cut flow chart
Best cuts using Smin maximisation script - New
Maximum Smin, for all combination of cuts:
| Best cut |
T5ttttDeg_4bodydec_mGo1300 |
T5ttttDeg_3bodydec_mGo1300 |
TTJets |
WJets_HT |
ZJets_HT |
QCD_HT |
T_tW |
All bg |
Smin = Eff./(5/2+sqrt(B)) |
| No cut |
23.47 |
24.17 |
4213.88 |
104.94 |
7.60 |
14906.68 |
72.73 |
19305.84 |
0.00707 |
| HTall>2050 |
15.74 |
15.24 |
283.71 |
30.66 |
2.09 |
1306.98 |
15.65 |
1639.08 |
0.01467 |
| DPhi<2.3 |
10.80 |
10.70 |
107.54 |
3.18 |
0.43 |
258.67 |
4.74 |
374.57 |
0.02025 |
| R>0.45 |
10.35 |
10.11 |
2.29 |
0.76 |
0.15 |
0.00 |
0.36 |
3.55 |
0.09538 |
| DPhi<2.7 && HTall>2050 |
11.78 |
11.38 |
82.04 |
5.30 |
0.57 |
258.67 |
5.10 |
351.69 |
0.02216 |
| R>0.45 && HTall>1200 |
10.34 |
10.11 |
2.29 |
0.76 |
0.15 |
0.00 |
0.36 |
3.55 |
0.09538 |
| R>0.36 && DPhi<2.75 |
13.46 |
13.33 |
2.29 |
1.11 |
0.30 |
0.00 |
0.00 |
3.70 |
0.12461 |
| R>0.36 && DPhi<2.75 && HTall>1100 |
13.46 |
13.33 |
2.29 |
1.11 |
0.30 |
0.00 |
0.00 |
3.70 |
0.12461 |
Using cuts (chosen by hand):
Background Estimation
Signal selection cuts:
- 2 Hadronic tops
- R > 0.4
- DPhi < 2.8
Introducing the method
ABCD Method:
- Define NTop<2 sideband, where the sideband is defined as 2 loose top-like jets:
- Has at least 2 AK8 jets with pt > 400, prunedMass > 140
- Sideband cut: NTopHad < 2 (at least one tau32 cut is inverted)
- Measure event yields in the R<0.4 sideband both for A) NTop<2 and C) NTop==2
- Fit NTop<2 sideband (A, B) with an exponential decay curve: exp(const + x * slope)
- Extract fit parameters and their error: const, slope
- Scale function by the event yield ratio C/A to get Signal region prediction: D
Recipe to plot very similar distributions by hand (for leading and subleading jets):
root -l
TChain c("c");
c.Add("/data/gridout/jkarancs/SusyAnalysis/B2G/TTreeNtuple/Feb28_edm_Feb20/WJetsToLNu_HT-600toInf/*.root/B2GTTreeMaker/B2GTree");
c.Draw("evt_R","jetAK8_Pt[0]>400&&jetAK8_Pt[1]>400&&jetAK8_prunedMass[0]>100&&jetAK8_prunedMass[1]>100&&evt_NTopHad<2");
c.Draw("evt_R","evt_NTopHad==2","SAME")
c.Draw("evt_R","evt_NTopHad==2&&evt_TTHadDPhi<2.8","SAME")
Plots - Extrapolation of R shape using an exponential fit in the NTop<2 SideBand
| TTbar |
QCD |
Comment |
 |
 |
R shape fit with exponential in the Ntop<2 sideband and NTop==2 signal bands. Range [0.15,1.0] for sideband, [0.15,0.4] for signal band. |
| W+Jets |
Z+Jets --> NuNu |
Comment |
 |
 |
R shape fit with exponential in the Ntop<2 sideband and NTop==2 signal bands. Range [0.15,1.0] for sideband, [0.15,0.4] for signal band, except for WJets for which low range is 0.2. |
| G + Jets |
Single top (tW channel) |
Comment |
 |
 |
R shape fit with exponential in the Ntop<2 sideband and NTop==2 signal bands. Range [0.15,1.0] for sideband, [0.15,0.4] for signal band. |
| DY + Jets |
Comment |
 |
R shape fit with exponential in the Ntop<2 sideband and NTop==2 signal bands. Range [0.15,1.0] for sideband, [0.15,0.4] for signal band. |
Table
To see how much background is there with
given statistics:
| Sample |
A (R<0.4, SB) |
B (R fit, SB) pred. |
B (R>0.4, SB) |
C (R<0.4, Sig.B.) |
D (R fit, Sig.B.) pred. |
D = B*C/A pred. |
D = B (R fit, SB) * C/A pred. |
D (R>0.4, Sig.B.) obs. |
Statistics in D |
| TTJets |
291.89 +- 9.77 |
1.26 +- 0.34 |
2.29 +- 0.86 |
578.22 +- 13.75 |
1.68 +- 0.40 |
4.53 +- 1.72 |
2.49 +- 0.68 |
2.29 +- 0.86 |
7 |
| WJets_HT |
37.42 +- 1.37 |
1.90 +- 0.28 |
2.12 +- 0.33 |
13.59 +- 0.83 |
0.66 +- 0.19 |
0.77 +- 0.13 |
0.69 +- 0.11 |
0.86 +- 0.21 |
17 |
| ZJets_HT |
3.76 +- 0.19 |
0.75 +- 0.07 |
0.92 +- 0.09 |
1.38 +- 0.11 |
0.25 +- 0.05 |
0.34 +- 0.05 |
0.28 +- 0.04 |
0.27 +- 0.05 |
29 |
| QCD_HT |
4260.50 +- 170.30 |
0.08 +- 0.11 |
0.00 +- 0.00 |
1493.78 +- 100.84 |
0.03 +- 0.07 |
0.00 +- 0.00 |
0.03 +- 0.04 |
0.00 +- 0.00 |
0 |
| T_tW |
12.72 +- 2.12 |
0.03 +- 0.05 |
0.00 +- 0.00 |
14.89 +- 2.30 |
0.06 +- 0.11 |
0.00 +- 0.00 |
0.03 +- 0.06 |
0.00 +- 0.00 |
0 |
| SUM |
4606.28 +- 170.60 |
4.02 +- 0.46 |
5.33 +- 0.93 |
2101.85 +- 101.80 |
2.68 +- 0.47 |
5.64 +- 2.99 |
3.51 +- 0.70 |
3.41 +- 0.89 |
|
Main backgrounds identified on tested samples - TTBar, QCD, W+Jets
http://hep.pha.jhu.edu:8080/susy/230
QCD background estimation technique
http://hep.pha.jhu.edu:8080/susy/115
Estimation of Uncertainties
--
JanosKarancsi - 2015-02-26
png 
Hungarian Academy of Sciences (MTA)
Department of High Energy Physics
