Select and skim events

Prerequisites and goal

You need access to the DAS signal file. The goal is to keep events with missing transverse momentum and at least two tight muons, while writing only the muon and displaced-dimuon collections needed later.

Prepare the skimmer config

cp tea/configs/das_exercises/task3_skimmer.py configs/skim_signal.py

Complete the event selection:

eventCuts = {
  "MET_pt": (50, 9999999),
  "nTightMuons": (2, 9999999),
}

Keep the relevant collection branches and their sizes:

branchesToKeep = (
  "Muon_*",
  "nMuon",
  "PatMuonVertex_*",
  "nPatMuonVertex",
  "MET_*",
  "genWeight",
)

Write inside the shared tutorial output tree:

treeOutputFilePath = "../results/tutorial/trees/tta_mAlp-12GeV_ctau-1e2mm.root"

Run

source tea/build.sh
cd bin
./skimmer --config skim_signal.py

Expected output

The terminal prints a cut flow. The output tree should contain fewer entries and fewer branches than the input:

rootls -t ../results/tutorial/trees/tta_mAlp-12GeV_ctau-1e2mm.root

Verify that the collections and their size branches are readable.

Next step

Calculate custom histograms from dimuon candidates.