Event Display (optional)

Overview

Teaching: 0 min
Exercises: 60 min

Questions

• How to make event displays of interesting signal simulation?

Objectives

• Learn to make event displays by choosing the interesting events in RECO format and open them with cmsShow

In this episode you will create event display of signal simulation events that pass the signal region selectionns

Find and pick events you want to view

We will first find the events that we want to view, by saving the run number, lumi section, and event number of the events in a text file.

Open a notebook

For this part, open the notebook called event_display.ipynb. This note book is very similar to the notebook in the previous episode, where we make the signal region selection. In addition, we save the run number, lumi section, and event number of the events that we want to view in a text file.

Now run the following code that will pick the ROOT files in the dataset that contain the events that you want based on the run/lumi/event numbers that you supplied:

edmPickEvents.py  "/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/RunIIFall17DRPremix-PU2017_rp_94X_mc2017_realistic_v11-v1/GEN-SIM-RECO” event_display.txt

The above command will print another command on the screen, like the following, copy and run it in the terminal:

edmCopyPickMerge outputFile=pickevents.root \
  eventsToProcess=1:10122482,1:1055072,1:1055666,1:1127224,1:12138657,1:1441939,1:1441963,1:2514929,1:2896338,1:4255433 \
  inputFiles=/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130001/B2A708EC-0D4E-EA11-8B93-0025905C2CBC.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130001/84696409-FC4D-EA11-A8CD-0CC47AFF0190.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130000/349A8AB2-BF4D-EA11-9AFF-00259073E43C.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130001/A4F52ADD-C94D-EA11-B339-7CD30AD091F0.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130000/04DB0102-BB4D-EA11-A197-7CD30AD0A78C.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130000/D6C63C14-484C-EA11-B04A-1866DA85DC8B.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130001/4A6C137D-CA4D-EA11-B475-001E67E7195C.root,/store/mc/RunIIFall17DRPremix/ggH_HToSSTobbbb_MH-125_TuneCP5_13TeV-powheg-pythia8/GEN-SIM-RECO/PU2017_rp_94X_mc2017_realistic_v11-v1/130001/DAD03CA8-624E-EA11-A67F-0242AC1C0504.root

Depending on how many events you’ve chosen, the process might long, don’t choose more than 10 events! Now you have a ROOT file called pickevents.root that contains the RECO format of the events you have chosen.

cmsShow is the program used to view event displays. cmsShow is now used with a web-based GUI. Before using the GUI, you need to copy your picked events file to cernbox.

Create a new directory in your personal cernbox. You will need to add viewer access to cms-vis-access

CernBox

Open the events with cmsShow

Once the file is in cernbox and you have given cms-vis-access viewer permission, you can view the event by going to cmsShow

You will now see a graphical interface like this:

Figure 5.1

Event display of a signal event from cmsShow.

By default the csc2DRecHits are not included in the display, go to Add Collectionon the left to add the rechits collections! Now you can skim through the events that you have selected to see if the clusters appear as you’ve expected.

Key Points

• Event displays allow us to view all available collections visually and scrutinize event topologies that are not possible with ntuples