TTbar τ + jets:Tau Selection Efficiency Study

William EdsonSUNY at AlbanyAnirvan Sircar

Efficiency Equation Definitions

• Signal Efficiency:εsig = 100 * Σ matched τ’s passing selection / Σ total matched τ’s

• Background Efficiency: εback = 100 * Σ unmatched τ’s passing selection / Σ total matched

τ’s

• Tau matching via getTruthMatch function in TNtupleAnalyzer code– total matched determined during Object Selection– matched/unmatched during tau cut (C7)

Background Efficiency Histograms

Top Row: LlhLoose, Medium, TightBottom Row: SigLoose, Medium, Tightplots made using mc11_7TeV.105200.T1_McAtNlo_Jimmy.merge.NTUP_TOP.e835_s1272_s1274_r3043_r2993_p834/

Signal Efficiency Histograms

Top Row: LlhLoose, Medium, TightBottom Row: SigLoose, Medium, Tightplots made using mc11_7TeV.105200.T1_McAtNlo_Jimmy.merge.NTUP_TOP.e835_s1272_s1274_r3043_r2993_p834/

Efficiency Study Total ResultsTauID True

matched τ’s

Unmatched Selected τ’s

Matched Selected

τ’s

Unmatched/Matched

Background Efficiency

Signal Efficiency

Amount of Events Passing

Selection

LlhLoose 1,018,264 14,664 39,104 0.375 1.44 3.84 2,599

LlhMedium 1,018,264 9,568 33,696 0.284 0.940 3.31 1,997

LlhTight 988,208 2,392 18,616 0.128 0.242 1.88 1,059

SigLoose 988,208 9,152 32,760 0.279 0.926 3.32 1,987

SigMedium 1,055,808 5,408 29,224 0.185 0.512 2.77 1,548

SigTight 988,208 1,560 16,432 0.095 0.158 1.66 859

Questions• Why do the amount of True Matched τ’s not

match?– Since all trials running on the same input

container the count during object selection should be the same• Must note: the three trials {SigMedium, LlhLoose and

LlhMedium} required multiple pbook retries to complete all subjobs• Could something have gone wrong during retrial of

subjobs?– If so this is a bug in pbook

Current/Future Work

• Plan on bringing input container locally for tests to finalize these numbers

• Running the efficiency tests using the background samples:– FullHad– J0 – J5