# Presentation: 758758

## Search for chargino and neutralino into  channel

- Sensitivity study for high pt scenario
- Ask for one high pt muon (high pt muon ID requirements)
- Ask for a second identified muon
- Clean up cut on the MET: MET > 10 GeV
- Optimization of the “standard cuts” (mass, Met, )
- Investigation of cuts which may remove the background which is left over

- 8/01/04

## Montecarlo samples 

-  Z & Z produced by the top group (min M>30 GeV)
-  checking next DY by John (min M >5 GeV)
-  **t-tbar** – OK
-  **b-bbar** – Not OK
-  200pb-1 per process produced by John, no events left
-  produced by ISAJET
-  **Diboson (WZ,ZZ,WW)** – OK?
-  top group samples not available
-  WZ and ZZ produced by Oscar
-  WZ, ZZ and WW produced by Reda (peter’s suggestion)
-  **W******** and W+jets** - OK

- Montecarlo samples

- _Version 5.3.3_
- ntuplizing again after cmp-cmx chi2 fixing

- 8/01/04

## ID Cuts for central muons

-  Muon has CMUP or CMX stub
-  X for CMU < 3 cm or CMU Chi2<9
-  X for CMP < 5 cm or CMP Chi2<9
-  X for CMX < 6 cm or CMX Chi2<9
-  Muon track
-  # COT Axial >= 3 (>=5 hits)
-  # COT Stereo >=2 (>=5 hits)
-  beam line corr d0 < 0.2 cm
-  track Chi2/(# hits -5) < 3
-  track Z0 < 60 cm
-  muon isolation < 0.1
-  muon Em E < 2 GeV - 2 + max(0,(pt-100)*0.0115) GeV
-  muon Had E < 3.5+8/pt GeV – 6 + max(0,(pt-100)*0.028) GeV
-  muon tot E > 0.1 GeV

- 8/01/04

## Invariant mass distribution

- After clean up cuts
- Dimuon event
- Muons from the same vertex
- Met > 10 GeV

- Remove resonances to be point independent
- [2.9;3.2] GeV
- [9.1;11] GeV
- [76,106] GeV

- 8/01/04

## Missing energy

- After invariant mass cut
- Met is corrected for muons
- Met is NOT corrected for jets

- 5 Gev bin

- Met > 25 GeV
- Allows us to release the geometrical cut

- 8/01/04

## Angular separation between 

- After met cut

- 4 degree bin

-  <170 degress

|  | susy | tt | Z | Z |
| --- | --- | --- | --- | --- |
|  <165 | 1704 | 679 | 14 | 15 |
|  <170 | 1752 | 702 | 14 | 23 |
|  <172 | 1764 | 710 | 23 | 24 |
|  <175 | 1788 | 722 | 30 | 32 |

- 8/01/04

## First comparison between signal and background

|  | SUSY | t-tbar | WZ | ZZ | Z | Z | S/√B |
| --- | --- | --- | --- | --- | --- | --- | --- |
| DiMuon | 7.3 | 5.8 | 2.4 | 0.06 | 7836 | 77 | 0.08 |
| Met >10  | 6.9 | 5.6 | 2.3 | 0.03 | 1006 | 51 | 0.21 |
| Mass | 6.7 | 4.6 | 1.0 | 0.02 | 84 | 50 | 0.57 |
| Met > 25 | 5.2 | 4.1 | 0.8 | 0.01 | 17 | 10 | 0.92 |
|  | 4.9 | 3.8 | 0.79 | 0.008 | 13 | 4.1 | 1.07 |

-  Normalized at 500 pb-1
-  Contributions from b-bbar, W+jets and W are negligeable
-  WW not included

- 8/01/04

## Remove heavy flavour

- After invariant   cut
- No jets with Et > 60 GeV (A)
- Or
- No events with more than 4 jets with any Et (B)

|  | SUSY | t-tbar | Z | Z | S/√B |
| --- | --- | --- | --- | --- | --- |
|  | 4.9 | 3.8 | 13 | 4.1 | ~ 1.07 |
| (A) | 4.8 | 2.0 | 6.3 | 3.7 | ~ 1.36 |

|  | SUSY | t-tbar | Z | Z | ~ S/√B |
| --- | --- | --- | --- | --- | --- |
|  | 4.9 | 3.8 | 13 | 4.1 | ~ 1.07 |
| (B) | 4.9 | 3.6 | 13 | 4.1 | ~ 1.08 |

- # jets vs jet et

- # jets

- Jet et

- Plot is NOT renormal.

- 8/01/04

## Ask for the third object

- After jet cut
- Third object is NOT a tight muon/electron
- As for now, third object is a muon or an electron with a track associated to it  (no additional resonance in the event)

|  | SUSY | t-tbar | b-bbar | WZ | ZZ | Z | Z | S/√B |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Third muon | 0.72 | 0.02 | 0 | 0.13 | 0.00 | 0.11 | 0 | 1.41 |

- Trilepton Workshop

|  | SUSY | t-tbar | WZ | ZZ | Z | Z | S/√B |
| --- | --- | --- | --- | --- | --- | --- | --- |
|  | 4.9 | 3.8 | 0.79 | 0.008 | 13 | 4.1 | 1.07 |
| Jet (A) | 4.8 | 2.0 | 0.77 | 0.007 | 6.3 | 3.7
 | 1.34 |
| Third obj. | 3.0 | 1.7 | 0.52 | 0.006 | 3.6 | 0.89 | 1.16 |

- 8/01/04

## Background still large

- Exploring
- Min  between muon and met
- Helps removing mis-measurement of the lepton energy which could increase the met in the DY sample
- The projection of the dilepton pt over the met direction

- Min  between muon and met

- 8/01/04

## Exploring
Min transverse mass of the system lepton-met
Upper cut to remove t-tbar ?
 will help for WW

- Min transverse mass of the system lepton-met
- Upper cut to remove t-tbar ?
-  will help for WW

- Background still large

- 8/01/04

## Timeline

- _Goal _is to have the sensitivity study for Dec 2nd
- _To do_,
- Finalize cuts by Monday
- Low met control region – first week of Nov.
- Z peak control region – second week of Nov.
- (high transverse mass region?)
- include fake rate and check – third week of  Nov.

- 8/01/04