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2015:groups:tools:ttjets [2015/06/04 15:06]
2015:groups:tools:ttjets [2015/09/16 14:58] (current)
rikkert.frederix [Samples generated by:]
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-setting up the page+====== ttbar + jets ======
-Existing CMS rivet routines for ttbar+//If you are interested in contributing please subscribe to the [[https://​​e-groups/​​searchValue=houches-2015-topics-tools-ttj|mailing list]]. You will be asked to log in with your CERN account. If you don't have a CERN account, please fill [[https://​​account/​Externals/​RegisterAccount.aspx|this form]] to create a lightweight account.//
 +The idea is to compare the latest version of all generators to be able to see what the current status of the predictions is. So far, this has never been done for top pair production, including multi-jet merging.
 +The set-up is the following:
 +  *13 TeV.
 +  *di-lepton top decays, with decays to e+mu, e+e and mu+mu.
 +  *Including hadronisation and underlying event/MPI.
 +  *Use MC truth for top reconstruction,​ i.e., the lepton, neutrino and b-jet momentum, using the "​ghost"​ particle definition. The leptons have to have |eta(l)|<​2.4 and pT(l)>20 GeV, b-jets must have |eta(b)|<​2.4 and pT(b)>​30GeV. Standard rivet dressing for the leptons with cone 0.1 (for both electrons and muons)
 +  *Jets ("​j"​) are defined with anti-kT algorithm, DeltaR=0.4, pT(jet)>​30GeV and |eta|<​4.7.
 +  *b-jets ("​b"​) have pT(jet)>​30GeV and |eta|<​2.4.
 +  *Light jets ("​lj"​) have pT(jet)>​30GeV and |eta|<​4.7,​ but do not contain a b, even if it's in the region 2.4<​|eta|<​4.7.
 +  *pT(top)
 +  *pT(ttbar)
 +  *pT(ttbar+jet)
 +  *m(t,tbar)
 +  *m(top)
 +  *DeltaPhi(l1,​l2)
 +  *DeltaPhi(lj1,​lj2)
 +  *m(b1,b2)
 +  *# of jets
 +  *# of b-jets
 +  *# of light jets
 +  *pT(j1), pT(j2), pT(j3), pT(j4)
 +  *pT(b1), pT(b2), pT(b3), pT(b4)
 +  *pT(lj1), pT(lj2), pT(lj3), pT(lj4)
 +  *asymmetries: ​
 +    *lepton
 +    *ttbar
 +  *Gap fraction: Q0, inclusive in Delta y
 +===== Samples generated by: =====
 +  *MadGraph5_aMC@NLO + Pythia8 with FxFx merging up to 2 extra jets at NLO
 +  *POWHEG+Pythia8 inclusive ttbar
 +  *POWHEG+pythia8 & 6, inclusive ttbar
 +  *…
 +**Rikkert Frederix:**
 +  *MadGraph5_aMC@NLO + Pythia8, inclusive ttbar
 +<​del>​**Simone Alioli:** POWHEG+Pythia8 ttbar+0,​1jet,​ with MinLo</​del>​
 +**Stefan Prestel:**
 +  *Pythia8+UNLOPS merging up to 2 extra jets at NLO
 +**Marek Schoenherr:​**
 +  *Sherpa+OpenLoops with merging up to 2 extra jets at NLO
 +**Christian Reuschle:**
 +  *Herwig++ (using e.g. MG5+OpenLoops) ttbar+0j NLO matched and ttbar+1j NLO matched
 +Note: the ttbar comparisons shown on the site may also be of interest and/or provide sanity checks:
 +  * E.g., http://​​query=plots,​ppppbar,​top-mc,​pTttbar ​
 +===== Starting point: Rivet routines and data cards =====
 +**Existing CMS rivet routines for ttbar**\\
 {{:​2015:​groups:​tools:​|}} {{:​2015:​groups:​tools:​|}}
 {{:​2015:​groups:​tools:​|}} {{:​2015:​groups:​tools:​|}}
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 {{:​2015:​groups:​tools:​|}} {{:​2015:​groups:​tools:​|}}
-Available CMS Monte Carlo samples: +**Available CMS Monte Carlo samples:**\\ 
-NNPDF30NLO (5 flavour, alphas=0.118),​ top mass=172.5 GeV, TuneCUETP8M1 (Tune:ee 7, Tune:pp 18)+with NNPDF30NLO (5 flavour, alphas=0.118),​ top mass=172.5 GeV, TuneCUETP8M1 (Tune:ee 7, Tune:pp 18)
-Powheg+Pythia8.205 ttbar card:+**Powheg+Pythia8.205 ttbar card:**\\
 {{:​2015:​groups:​tools:​tt_hdamp_nnpdf30_13tev_powheg.input.txt|}} {{:​2015:​groups:​tools:​tt_hdamp_nnpdf30_13tev_powheg.input.txt|}}
-madgraph_aMC@NLO+Pythia8.205 0,1,2 jets NLO merged cards:+**madgraph_aMC@NLO+Pythia8.205 0,1,2 jets NLO merged cards:**\\
 {{:​2015:​groups:​tools:​tt012j_5f_ckm_nlo_fxfx_customizecards.dat.txt|}} {{:​2015:​groups:​tools:​tt012j_5f_ckm_nlo_fxfx_customizecards.dat.txt|}}
 {{:​2015:​groups:​tools:​tt012j_5f_ckm_nlo_fxfx_proc_card.dat.txt|}} {{:​2015:​groups:​tools:​tt012j_5f_ckm_nlo_fxfx_proc_card.dat.txt|}}
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 +===== Preliminary results ======
 +**From CMS**
 +A Rivet routine enables to get distributions for all the observables listed above, ​ [[http://​​ebouvier/​TOPRivetForLesHouches/​|]],​ which is making use of a helping class, [[http://​​ebouvier/​TOPRivetForLesHouches/​|]] and [[http://​​ebouvier/​TOPRivetForLesHouches/​PseudoTop.hh|PseudoTop.hh]].
 +This routine has been run for Powheg + Herwig++ on the one hand, and Powheg + Pythia 8 on the other hand. Distributions are gathered [[http://​​ebouvier/​TOPRivetForLesHouches/​plots/​CMS_AN_PseudoTop/​index.html|here]],​ while ''​.yoda''​ files can be found [[http://​​ebouvier/​TOPRivetForLesHouches/​Herwig.yoda|here for Powheg + Herwig++]] and [[http://​​ebouvier/​TOPRivetForLesHouches/​Pythia8.yoda|there for Powheg + Pythia 8]]. Lepton and ttbar asymmetries and the gap fraction are represented with respect to the ttbar-system mass. In average, they are:
 +^                                          ^ Powheg + Herwig++ ^ Powheg + Pythia 8 ^
 +^ Lepton asymmetry ​                        | 0.0036 ​           | 0.0006 ​           |
 +^ ttbar asymmetry ​                         | 0.007             | 0.005             ​| ​
 +^ Gap fraction ​                            | 0.436             | 0.444             |
2015/groups/tools/ttjets.1433423194.txt.gz · Last modified: 2015/06/04 15:06 by josh.bendavid