PH4100 MSci Project - Simulated event samples

General comments

All samples for this project are simulated at a centre-of-mass energy of 13 TeV and with the 2017 configuration for both the ATLAS detector and the LHC.

(Technical details: August 2019 ntuple production, with release 21.2.86; L2 ntuples, i.e. small ntuples, only 288 variables. All the necessary weights are already included in the ntuples. This includes, specifically, weight_normalise, therefore no need to calculate it on the fly.)

The samples are all available on linappserv from the directory

/scratch0/dthomas/DataMCComparison_03_2018/ttHScripts/DaveExamples_08_2019_Run2_AFII/ge2jge2b

The specific samples for this project are in the following root files:

 27283690485 Oct  3 17:00 ttH_PoPy8_FS_17.root
  2331996673 Oct  9 09:19 ttbar_PP8_dil_AFII_17_0.root
104273559846 Oct  9 10:39 ttbar_PP8_dil_AFII_17_1.root
 13461914616 Oct  3 17:09 ttbb_AFII_17.root
   543474523 Oct  4 12:02 singletop_FS_17.root
  6904819778 Oct  6 11:18 ttV_FS_17.root
   315459992 Oct  6 11:20 ttWW3t4t_tWZ_FS_17.root
     8988402 Oct  6 10:54 Wjets_FS_17.root
  2794320342 Oct  6 10:57 Zjets_FS_17.root
   467852988 Oct  4 12:02 diboson_FS_17.root

In these filenames:

• "FS" indicates Full Simulation of the ATLAS detector
• "AFII" indicates Fast Simulation (ATLFAST II) of the ATLAS detector
• "17" indicates 2017 confiuration

Signal sample: ttH

 27283690485 Oct  3 17:00 ttH_PoPy8_FS_17.root

The signal sample was generated with PowHeg + PYTHIA 8, and it includes all Higgs decays.

Specific Higgs decays can be selected using the information given here: selecting a specific Higgs decay mode.

(This sample includes 3 DSIDs: mostly events from 34345 ("2l"), but also some events with two reconstructed leptons from 346343 ("0l") and 346344 ("1l").)

Background samples

ttbar

  2331996673 Oct  9 09:19 ttbar_PP8_dil_AFII_17_0.root
104273559846 Oct  9 10:39 ttbar_PP8_dil_AFII_17_1.root

The ttbar background consists of a top + anti-top quark pair, with additional jets. The sample was generated with PowHeg + PYTHIA 8 (5FS = five-flavour scheme). Note that "dil" in the filenames does not mean that only the dilepton final state was generated; it means that these are the ntuples for the dilepton analysis. This sample includes all of tt + light jets, tt + c-jets and tt + b-jets. The channels included in this sample are: "all hadronic", "non-all hadronic" and "dilepton"; the first two are orthogonal samples, but "non-all hadronic" includes "dilepton" events. For the dilepton analysis there are two main options: either use just the "dilepton" DSIDs, or use all three channels; for the latter it is therefore necessary to remove overlapping dilepton phase space - this is done using the truth_top_dilep_filter variable in the ntuples.

tt+bb

 13461914616 Oct  3 17:09 ttbb_AFII_17.root

This is a dedicated sample for the production of a top-antitop-quark pair plus a b and anti-b pair (4FS = four-flavour scheme). If this sample is used (which is recommended, as this is the main background) the overlap with the tt+bb events already included in the "ttbar" sample above has to be removed. This is done using the HF_SimpleClassification variable in the ntuples.

single top

   543474523 Oct  4 12:02 singletop_FS_17.root

Single top-quark production.

ttV

  6904819778 Oct  6 11:18 ttV_FS_17.root

Production of a top + anti-top-quark pair with an associated gauge boson (V = W or Z).

ttWW3t4t

   315459992 Oct  6 11:20 ttWW3t4t_tWZ_FS_17.root

This sample includes several rare processes with top-quarks: ttWW, 3t and 4t, as well as tWZ.

W+jets, Z+jets

     8988402 Oct  6 10:54 Wjets_FS_17.root
  2794320342 Oct  6 10:57 Zjets_FS_17.root

Production of a single W or Z gauge boson, with additional jets.

di-boson

   467852988 Oct  4 12:02 diboson_FS_17.root

Production of two heavy gauge bosons: WW, WZ and ZZ.

Pedro Teixeira Dias - 21 Oct 2019

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