Muon Identification Efficiencies Using Tag &Probe

Tag & Probe Configuration

TAG A Tag muon is required to pass the tight muon selection ie:

• pT>20 GeV
• |eta|<2.1
• Identified as both tracker and standalone muon
• Track muon selection ie pixel hits>0 & hits in the tracker>10
• Muon matches to atleast 2 muon stations
• D0<2 mm & Chi2/ndof<10
• Hits in the muon chamber used in the global muon fit>0
• Relative Combined isolation<0.15
• It should match to the trigger object

PROBE

• pT>5 GeV & |eta|<2.1

TAG PROBE PAIR

• Tag muon + probe muon with opposite charge
• Invariant mass of tag&probe pair lies between 60-120 GeV

FITTING METHOD

• Used fitting procedure from Tag&Probe official package ie SimplifiedElectronTagAndProbe.C
• Signal : Convolution of Breit-Wigner with Crystall Ball
• Background : Exponential

Datasets Used

• DATA /Mu/Run2010B-PromptReco-v2/RECO (32.29 pb-1)

/Mu/Run2010A-Sep17ReReco_v2/RECO (3.00pb-1)

• MC DYT0MuMu_M-20_CT10_TuneZ2_7TeV-powheg- pythia/Fall10- START38_V12-v1/GEN-SIM-RECO

Efficiencies

A Probe muon is used to calculate 6 efficiencies:

1. StandAlone Muon(STA) : A probe muon is required to pass all the cuts involving the inner tracker.
2. Tracker Muon(TRK) : A probe muon must be reconstructed as a good quality standalone muon.
3. Muon ID : A probe muon must pass all the cuts except for the cuts on D0 and Chi2.
4. Muon ISO : A probe muon must pass all the cuts except for the isolation cut.
5. Muon Trigger : A probe muon must pass all the cuts except for the HLT.

An overview of used probes and passing probes are shown in table :

Resulting Plots

Efficiency plots as a function of pt and eta , Scale factor as a function of pt are shown below

• StandAlone Muon

• Tracker Muon

• Muon ID

• Muon Iso

• HLT_Mu9

• HLT_Mu11

• HLT_Mu15_v1

• Summary Table for efficiency