# Presentation: 326680

## Efficiency in Plug Electron Identification

- Julia Novak
- Purdue University
- CDF Collaboration

## Plug Electron Channel

- Looking in Drell-Yan sector
- Plugs from Z-mass peak
- One tight electron and one loose
- Require one central electron
- Tighter ET cut
- Match with one plug candidate
- Series of clean-up and identification cuts
- Side band subtraction to reduce background

## Data Samples and Statistics

- Data sample: bewk0d
- 3,000,000 events
- Opposite sign electrons passing clean-up cuts: 6404
- Of those that were plug: 1981
- Those passing all ID cuts: 1466
- Monte Carlo sample: sexo8t
- 1,000,000 events
- Opposite sign electrons passing clean-up cuts: 70986
- Of those that were plug: 25121
- Electrons passing all ID cuts: 19971
- Good Run Filter: DQM_V7:101

## The Method

- Side Band Subtraction
- Acceptance region from 80-100 GeV
- Side band regions 60-80 GeV and 100-120 Gev
- Side Bands are used to estimate background
- .
- .
- Future study of Same Sign Subtraction planned

## Plug Cutting Variables

- Clean-up Cuts
- ET > 4GeV
- Track PT > 2GeV
- ΔΦ > 2.7rad
- Opposite Sign
- Charge = ±1
- N(Silicon Hits) > 0
- |Z°| < 60cm
- IsPlug() = true
- Require one track

## Plug Cutting Variables

- Identification Cuts
- HadEm < 0.05
- χ2PEM3x3 < 10
- PES 5/9 U > 0.65
- PES 5/9 V > 0.65
- E/P < 3
- ETiso/ET > 0.2
- ΔR(PEM-PES) < 3

## Efficiency on Identification Cuts

**Data**
- HadEm: 99.675 +/- 0.187
- χ2PEM3x3: 95.437 +/- 0.590
- PES 5/9 U: 99.103 +/- 0.260
- PES 5/9 V: 99.388 +/- 0.235
- E/P: 88.295 +/- 0.852
- ETiso/ET: 96.809 +/- 0.498
- ΔR(PEM-PES):  98.961 +/- 0.292
- All Cuts: 75.706 +/- 0.596

**Monte Carlo**
- HadEm: 99.236 +/- 0.066
- χ2PEM3x3: 95.702 +/- 0.151
- PES 5/9 U: 99.685 +/- 0.044
- PES 5/9 V: 99.664 +/- 0.045
- E/P: 89.044 +/- 0.224
- ETiso/ET: 98.456 +/- 0.098
- ΔR(PEM-PES): 98.983 +/- 0.076
- All Cuts: 79.701 +/- 0.160

## Efficiency Histograms

- All Cuts

## Efficiency Histograms

- Number of Vertices

- DeltaR (PEM-PES)

- Chi^2 PEM 3x3

- Corrected Isolation

## Efficiency Histograms

- E/P

- Had/Em

- PES 5/9  U

- PES 5/9 V

## Scaling Factors for Data to MC

- HadEm: 1.00442 +/-  0.198
- χ2PEM3x3: 0.997229 +/- 0.609
- PES 5/9 U: 0.994157 +/- 0.264
- PES 5/9 V: 0.99723 +/- 0.239
- E/P: 0.991593 +/- 0.881
- ETiso/ET: 0.983275 +/- 0.507
- ΔR(PEM-PES):  0.999771 +/- 0.302
- All Cuts: 0.949876 +/- 0.617

## Scaling Factor Histograms

- All Cuts

- Corrected Isolation

- Chi^2 PEM 3x3

- DeltaR (PEM-PES)

## Scaling Factor Histograms

- E/P

- Had/Em

- PES 5/9  U

- PES 5/9 V

## Cut Efficiency Studies

- Efficiency for DeltaPhi

- Efficiency for Had/Em

## Identification Variables

- Et

- Pt

- Invariant Mass

- Events passed all clean-up and identification cuts

## Identification Variables

- Phi

- Chi^2 PEM3x3

- DeltaPhi

- Eta

## Identification Variables

- Had/Em

- PES 5/9 U

- E/P

- PES 5/9 V

## Error Calculation

- Method used outlined in Blocker’s note, CDF Note #7168
-      number in signal region passing all cuts
-         number in signal region passing all cuts except one of interest,       number in side bands passing all cuts,        number in side bands passing all cuts except one of interest,     scale factor
- Efficiency:
- Standard error propagation:

## Isolation: Corrected v. Uncorrected

- Currently IsoCut = IsoCorr/ EtCorr
- Substituted Iso for IsoCorr
- No large deviation observed
- Iso:
- Efficiency on Isolation Cut: 96.871 +/- 0.495
- Efficiency on All Cuts: 75.833 +/- 0.594
- IsoCorr:
- Efficiency on Isolation Cut: 96.809 +/- 0.498
- Efficiency on All Cuts: 75.706 +/- 0.596
- IsoCorr sometimes gives negative value
- The correction needs to be studied

## Transverse Energy Comparison

- Corrected Isolation

- Uncorrected Isolation

## Vertex Correction

- Correction:
- Substituted:
- Isolation w/o Correction:
- Efficiency on Isolation Cut: 96.809 +/- 0.498
- Efficiency on All Cuts: 75.706 +/- 0.596
- Isolation w/ Correction:
- Efficiency on Isolation Cut: 97.204750 +/- 0.466961
- Efficiency on All Cuts: 75.865829 +/- 0.597943
- Less than half a percent deviation observed
- Should we tailor isolation cut to analysis

## Transverse Energy Comparison

- Isolation w/o Correction

- Isolation w/ Correction

## N(Vertex) Clean-Up Cut

- A minimum requirement on vertex number set at clean-up level
- Requirement imposed upon both electrons
- Event must have one or more vertex
- Isolation w/o Vertex Requirement:
- Efficiency on Isolation Cut: 96.809 +/- 0.498
- Efficiency on All Cuts:75.706 +/- 0.596
- Isolation w/ Vertex Requirement:
- Efficiency on Isolation Cut: 95.973785 +/- 0.641514
- Efficiency on All Cuts: 74.464218 +/- 0.680237
- Larger deviation found

## Transverse Energy Comparison

- Isolation w/ Requirement

- Isolation w/o Requirement

## Efficiency on Identification Cuts

**Data with Side Band**
- HadEm: 99.675 +/- 0.187
- χ2PEM3x3: 95.437 +/- 0.590
- PES 5/9 U: 99.103 +/- 0.260
- PES 5/9 V: 99.388 +/- 0.235
- E/P: 88.295 +/- 0.852
- ETiso/ET: 96.809 +/- 0.498
- ΔR(PEM-PES):  98.961 +/- 0.292
- All Cuts: 75.706 +/- 0.596

**Data with Same Sign**
- HadEm: 99.380 +/- 0.196
- χ2PEM3x3: 95.187 +/- 0.592
- PES 5/9 U: 99.195 +/- 0.282
- PES 5/9 V: 99.195 +/- 0.239
- E/P: 89.497 +/- 0.853
- ETiso/ET: 96.332 +/- 0.542
- ΔR(PEM-PES): 98.828 +/- 0.294
- All Cuts:74.860 +/- 0.584

## Efficiency on Identification Cuts

**Monte Carlo with Side Band**
- HadEm: 99.236 +/- 0.066
- χ2PEM3x3: 95.702 +/- 0.151
- PES 5/9 U: 99.685 +/- 0.044
- PES 5/9 V: 99.664 +/- 0.045
- E/P: 89.044 +/- 0.224
- ETiso/ET: 98.456 +/- 0.098
- ΔR(PEM-PES): 98.983 +/- 0.076
- All Cuts: 79.701 +/- 0.160

**Monte Carlo with Same Sign**
- HadEm: 99.185 +/- 0.058
- χ2PEM3x3: 95.588 +/- 0.131
- PES 5/9 U: 99.375 +/- 0.050
- PES 5/9 V: 99.349 +/- 0.052
- E/P: 91.012 +/- 0.184
- ETiso/ET: 97.138 +/- 0.103
- ΔR(PEM-PES): 98.380 +/- 0.079
- All Cuts: 78.611 +/- 0.131

## ET Dependence for Isolation

- Isolation for Side Band

- Isolation for Same Sign

## ET Dependence for EoverP

- E over P for Side Band

- EoverP for Same Sign

## Same Sign ET Dependence

- All Cuts

## Identification Variables

- Invariant Mass

- Et

- Pt

- E/P

## Identification Variables

- Chi^2 PEM3x3

- Eta

- Phi

- PES 5/9 U

- PES 5/9 V

## Preliminary Stop Efficiency

**Stop Monte Carlo**
- HadEm: 100.00 +/- 0.000
- χ2PEM3x3: 83.333 +/- 10.758
- PES 5/9 U: 83.333 +/- 10.758
- PES 5/9 V: 100.000 +/- 0.000
- E/P: 125.000 +/- 24.206
- ETiso/ET: 71.429 +/- 12.074
- ΔR(PEM-PES): 100.000 +/- 0.000
- All Cuts: 55.555 +/- 4.278

**Using old Stop Ntutples**
- stopMC_170_75
- 18,000 events
- Total number of 2nd electrons that were os: 352
- Total number of 2nd electrons that were os and plug: 29
- Total number of 2nd electrons that were os and plug and passed all cuts: 10

## Conclusion

- Good agreement with Alon Attal
- CDF Note #7345
- Using isolation cut with corrected Isolation variable and corrected ET variable
- PPR/PEM not studied
- Need to study data at lower pT
- Further study of Same Sign Subtraction planned for future

## References

*ID Efficiencies for Medium E**T** Plug Electrons*, Alon Attal, CDF Note #7345
*Uncertainties on Efficiencies*, Craig Blocker, CDF Note #7168
*ID Efficiencies for Low Energy Electrons*, Giulia Manca, Beate Heinemann, Martin Griffiths, CDF Note #7233
*Underlying Event Studies and Photon ID Efficiencies in Run II*, Doug Benjamin, Alfred Goshaw, Michael Kirby, CDF Note #6608