It’s the part of the dataset name before the second 'slash', i.e. for the dataset
/GluGluToHToZZTo4L_M-550_7TeV-minloHJJ-pythia6-tauola/Summer11LegDR-PU_S13_START53_LV6-v1/AODSIM
the dataset name is
GluGluToHToZZTo4L_M-550_7TeV-minloHJJ-pythia6-tauola.
CMS uses the following convention for this name:
PROCESS_RANGETYPE-RANGELOWtoRANGEHIGH_FILTER_TUNE_COMMENT_COMENERGY-GENERATOR,
where
PROCESS is the physics process in the sample, e.g. QCD, TT, W, DYRANGETYPE is the variable the sample is binned in, e.g. PT, MRANGELOW is the lower bound of that range in GeV, e.g. 0, 10, 200RANGEHIGH is the upper boundFILTER denotes information on additional filters appliedTUNE is the underlying-event tune (e.g. TuneZ2Star)COMMENT for additional commentsCOMENERGY is the centre-of-mass collision energy, e.g. 7TeV, 10TeVGENERATOR is the generator used, e.g. pythia6, herwigpp, sherpaSome details on all these parts are below.
To unify this part CMS uses the following conventions:
W, Z, Mu, Tau, E, Nu, Wplus, H, Jets, Tbar, B, BbarTo, e.g. WToENu, HToWWTo2L2NuGluGluToWW with respect to WWWplus is used if only W+ is in the sample, and Tbar if an anti-top is present; WplusWminus is not used for W-pair production and a top-antitop pair is represented with TT2E2Nu is used rather then EENuNuThe following conventions are applied for the most common particles:
| Particle | Keyword | modifications if needed |
|---|---|---|
| electron/positron | `E` | `Eminus`, `Eplus` |
| muon | `Mu` | `Muplus`, `Muminus` |
| tau | `Tau` | `Tauplus`, `Tauminus` |
| charged lepton | `L` | |
| neutrino | `Nu` | `Nue`, `Numu`, `Nutau`, `Nuebar`,… |
| W | `W` | `Wplus`, `Wminus`, `Wprime` |
| Z (no photon) | `Z` | `Zprime` |
| Z/photon (Drell-Yan) | `DY` | |
| photon | `G` | |
| gluon | `Glu` | |
| top | `T` | `Tbar`, `Tprime` |
| bottom | `B` | `Bbar`, `Bprime` |
| quark | `Q` | `Qbar` |
| jet | `Jet` | `Jets` for more than one (inclusive); `1Jet`, `2Jets`, … for exclusive |
| jet | `J` | for decay products, if both quarks and gluons are produced |
This part denotes the variable (if at all) in which the sample is binned. Typical possibilities are Pt (pthat), M (inv. mass), as well as the range for this variable. This part of the name may also be used togther with M to specify the mass of a particle that is used as a parameter (e.g. Higgs mass, Z′ mass, …). Examples are
Pt-100To200 for binning in pthat from 100 GeV to 200 GeVPt-50 if there is only a lower cut on pthatM-30 as a lower inv. mass cut (e.g. in Drell-Yan)M-160 for Higgs mass of 160 GeVIf needed, the variable may be accompanied by specification of the particle in the process on which the cut is applied:
PtW-300 if there is a lower cut on the W pthatThis part of the dataset name may be dropped if there is no binning, inv. mass cuts etc.
This part specifies a GEN-level filter for the production, if present. The part is however not standardised; here a few examples:
EMEnriched: some filter — enriching the sample with electrons/photons — is appliedMuEnriched: GEN-level filter on MuonsMuEnrichedPt5: cut on GEN-level muons of 5 GeVUsed only if necessary information could not be put in any of the other fields. e.g. only QCD or only EWK production, special selections etc.
Units are added to integers in COMENERGY, i.e. 7TeV, 10TeV, 900GeV, 2360GeV and so on.
The generators used are:
| Generator | Keyword |
|---|---|
| Pythia6 | `pythia6` |
| Pythia8 | `pythia8` |
| Herwig6 | `herwig6` |
| Herwig++ | `herwigpp` |
| Sherpa | `sherpa` |
| MadGraph | `madgraph` |
| MadGraph **not showered with Pythia6** | `madgraph-herwigpp`, … |
| Alpgen | `alpgen` |
| Alpgen **not showered with Pythia6** | `alpgen-herwig6`, … |
| MC@NLO | `mcatnlo` |
| MC@NLO **not showered with Herwig6** | `mcatnlo-pythia6`, …`` |
| POWHEG | `powheg` |
| POWHEG **not showered with Pythia6** | `powheg-pythia8`, … |
| HARDCOL | `hardcol` |
| BCVEGPY 2 | `bcvegpy2` |
| … | … |
If a specialised decay tool was used, it was appended to the name, e.g. if EvtGen was used after Pythia6, the keyword would be …-pythia6-evtgen.