# Presentation: 785005

## Search for chargino and neutralino

**    **

_**Talk outline**_
** ****Analysis strategy **
** ****Expected sensitivity**
** ****Control region study **

_**Anadi Canepa**_**, O.González, E.Lytken; D.Bortoletto**
**(Purdue University, IN)**

**High p****t**** Dimuon channel with additional lepton**

*CDF note in preparation*

- 8/01/04

## Analysis strategy

**Distribution of transverse momentum of muons in benchmark point**

**Leading muon mostly p****t ****> 20 GeV/c**** **
**Exploit single high p****t**** muon triggers**

**Point (a) : m****0 ****= 100 GeV, m****1/2****= 180 GeV, tan******** = 5, A****0 ****= 0, ******** > 0**

-  **Blind analysis**** performed as counting experiment**
** ****Search for ****trilepton signal**** : **_**2 muons & additional lepton**_** (e or ********)**

- 8/01/04

## Data set validation: bewk2d

**MUON_CMUP18    ********  = 0.899 +/- 0.006 **
**MUON_CMX18   ********  = 0.968 +/- 0.005 **
**(CDF 7367)**

**Z invariant mass flat in time **

**Maybe smearing of the Z peak needed since mean differs from 91.2 GeV ? **

**Good Run List v7 **
**(CMUP-CMX-Electron-NoSilicon)**
**Luminosity = 346 pb****-1**

- 8/01/04

## Leading muon pt > 20 GeV/c
EWK muon ID
Central loose muon
Non-leading muon pt > 5 GeV/c
INTERMEDIATE pt muon ID
Same as above but:
pt  > 5 GeV
Had Energy < (3.5 + pt/8) GeV
Stub matching relaxed from X to X  or 2 requirement
Third lepton
Either CMIO (pt > 10 GeV)  or loose central electron (Et > 5 GeV) 

**Leading muon** pt > 20 GeV/c
- EWK muon ID
- Central loose muon
**Non-leading muon** pt > 5 GeV/c
- INTERMEDIATE pt muon ID
- Same as above but:
- pt  > 5 GeV
- Had Energy < (3.5 + pt/8) GeV
- Stub matching relaxed from X to X  or 2 requirement
**Third lepton**
- Either CMIO (pt > 10 GeV)  or loose central electron (Et > 5 GeV)

**MUON_CMUP SF  = 0.881 +/- 0.01**
**MUON_CMX  SF  = 0.997 +/- 0.0017**
**(CDF 7367)**

**MUON_CMUP   reconstruction SF  = 0.9315 +/- 0.0047** **(CDF 7367)**
**MUON_CMX  reconstruction SF  = 0.987 +/- 0.0026 ****(CDF 7367)**
- Intermediate pt muon isolation SF = 0.915 +/- 0.055

**MUON_CMUP  id SF 0.99 =0.005**
**MUON_CMX id SF 1.00 =0.085**
**(CDF 7197)**

***new p******t****** range ***

**CMIO  SF 1.0 (CDF)**
**Loose Electron S.F 1.0 (CDF)**

- 8/01/04

## We split background contributions into two categories
3 real leptons (three leptons at generator level)
tt-bar 
bb-bar 
ZZ; WZ 

2 real muons & additional lepton (CMUP, CMX or CMIO)
Drell Yan / WW & Fake lepton
Two ID muons (estimated from data)
Drell Yan / WW & electron from conversion* 
Two muons &  radiated off from leptons at generator level

(*) Fake rate estimated in jet samples with few leptons; leptons from decay of  radiated off from leptons NOT included in fake rate

*We split background contributions into two categories*
**3 real leptons **(three leptons at generator level)
**tt-bar **
**bb-bar **
**ZZ; WZ **
**2 real muons & additional lepton (CMUP, CMX or CMIO)**
**Drell Yan / WW & Fake lepton**
**Two ID muons (estimated from data)**
**Drell Yan / WW & electron from conversion********* **
**Two muons & ******** radiated off from leptons at generator level**
- (*) Fake rate estimated in jet samples with few leptons; leptons from decay of  radiated off from leptons NOT included in fake rate

- 8/01/04

## We split background contributions into two categories
2 real leptons (two leptons at generator level)
Drell Yan
tt-bar 
bb-bar 
ZZ; WZ; WW

1 real muons & additional lepton (CMUP or CMX)
W & Fake lepton
One ID muon (estimated from W decaying to +1pt)

*We split background contributions into two categories*
**2 real leptons **(two leptons at generator level)
**Drell Yan**
**tt-bar **
**bb-bar **
**ZZ; WZ; WW**
**1 real muons & additional lepton (CMUP or CMX)**
**W & Fake lepton**
**One ID muon (estimated from W decaying to ********+1pt)**

- 8/01/04

## Heavy flavor
Oscar generated a large sample of b-bbar decaying into trilepton
Trilepton contribution estimated by applying a scaling which takes into account acceptance and reconstruction efficiency 
WZ/* 
Found a problem at generator level: MADGRAPH scales the event depending on the invariant mass with a factor based on the charge of the leptons involved
Else produced new samples; start looking at that
For this talk, used WZ sample validated earlier (PYTHIA)

- Heavy flavor
- Oscar generated a large sample of b-bbar decaying into trilepton
- Trilepton contribution estimated by applying a scaling which takes into account acceptance and reconstruction efficiency
- WZ/*
- Found a problem at generator level: MADGRAPH scales the event depending on the invariant mass with a factor based on the charge of the leptons involved
- Else produced new samples; start looking at that
- For this talk, used WZ sample validated earlier (PYTHIA)

- 8/01/04

## WZ/* MADGRAPH samples

- 8/01/04

## Late February the calculation of fake rate changed 
To get better agreement data-MC, the fakeable track must be isolated
Fake rate for CMIO looks too high (needs investigation)
In signal region, contribution from 2 muons + 1 fake:
0.05 if CMUP or CMX or loose electron
0.15 if CMUP or CMX or CMIO or loose electron
Plan to run the fake rate calculation 

**Fake Rate for CMIO**

- Late February the calculation of fake rate changed
- To get better agreement data-MC, the fakeable track must be isolated
- Fake rate for CMIO looks too high (needs investigation)
- In **signal region**, contribution from 2 muons + 1 fake:
- 0.05 if CMUP or CMX or loose electron
**0.15 if** CMUP or CMX or **CMIO** or loose electron
- _Plan to run the fake rate calculation_

| N events 2 + fake |  |
| --- | --- |
| Electron | 1914 |
| CMUP | 23 |
| CMX  | 19 |
| CMIO | 9 |

- 8/01/04

## With the implementation of new cuts, the event of DY+conversion in the Drell Yan sample removed
Move to Z sample for such an evaluation
Sample is 4.11.2 so the systematics will be affected by material

- With the implementation of new cuts, the event of DY+conversion in the Drell Yan sample removed
- Move to Z sample for such an evaluation
- Sample is 4.11.2 so the systematics will be affected by material

- 8/01/04

## Monte Carlo Samples

- _Monte Carlo Samples_
_**tt-bar**_
**official ttopel  ****Luminosity = pb****-1**
**PYTHIA**
_**bb-bar**_
**Multilepton Group Sample **
**direct production, gluon splitting, flavor excitation **
**ISAJET**
_**WZ**_
**Multilepton Group Sample ****Luminosity = pb****-1**
**PYTHIA**
_**WW, DY and ZZ/**__****__*****_
**Multilepton Group Sample **
**WW Luminosity = 30,324 pb****-1 ****(******** = pb)**
**DY Luminosity = 901 pb****-1**
**ZZ Luminosity = pb****-1**
**PYTHIA**

- For scaling only

- 8/01/04

## Fake rate implementation

**Looks for fake objects in a given **_**dimuon event**_** ****in DATA**

** ****If ****1 fakeable object**** (fake rate f.r****1****)**
** ****the event goes through the analysis cuts with the ****fake object as third lepton**** and a weight = f.r****1**
** ****If ****2 fakeable ****objects p****t1**** > p****t2**** (fake rate f.r****1****; f.r****2****)**
** ****the event goes through the analysis cuts with the fake object (1) as third lepton and with a weight = f.r****1**
** ****the event goes through the analysis cuts a second time with the fake object (2) as third lepton and with a weight = f.r****2****∙(1-****f.r****1****)**

- 8/01/04

## The event is rejected if triggered CMUP18_Volunteer only
The event is rejected if at least one jet with  < 0.1 and if at least one jet in the chimney (improvement up to 4%)
The event is rejected if outgoing pair
Still cosmic contribution : cut on acollinearity

**Clean up cuts**

- The event is rejected if triggered CMUP18_Volunteer only
- The event is rejected if at least one jet with  < 0.1 and if at least one jet in the chimney (improvement up to 4%)
- The event is rejected if outgoing pair
*Still cosmic contribution *: cut on acollinearity

- 8/01/04

## Each event is scaled for ID efficiency and trigger efficiency
The weight of the event is w = trig ∙ SF
The weight of the event is scaled for the SF associated to each lepton in the event 
SF = sf(lepton1)∙sf(lepton2) ∙ sf(lepton3)
The weight of the event is scaled for the trigger efficiency
If 1 CMUP muon, trig  = CMUP
If 1 CMX muon, trig = = CMX
If 1 CMUP & 1 CMX muon, trig = 1.0
If 2 same type muon, trig =  ∙(2- )

- Each event is scaled for ID efficiency and trigger efficiency
- The weight of the event is **w = ********trig**** ****∙**** SF**
- The weight of the event is scaled for the SF associated to each lepton in the event
- SF = sf(lepton1)∙sf(lepton2) ∙ sf(lepton3)
- The weight of the event is scaled for the trigger efficiency
- If 1 CMUP muon, ******trig****  **= CMUP
- If 1 CMX muon, ******trig** = = CMX
- If 1 CMUP & 1 CMX muon, ******trig** = 1.0
- If 2 same type muon, ******trig** =  ∙(2- )

- 8/01/04

## Analysis cuts

**TWO CENTRAL muons and a third central lepton**
** ****lepton pt is Beam Constrained Pt**
******R****ll**** > 0.4**
******Z****ll**** **** < 4 cm**
**if electron, checked for conversion **
-  maxSep = 0.1 ; Cot < 0.02
-  efficiency  = 99.8 ± 0.3 % (Kobayashi)
**Kine****matic cuts**** ****to reduce background**
**Mass cut**
**Jet cut **
**ME****t**** cut**

- 8/01/04

## New Jet Energy Correction implemented
JetCorr04a
In Jet collection, jet counted if :
Raw Et > 10 GeV
EmFract < 0.9
Rjet-lepton > 0.4

The Jet Et is corrected at L5 if  < 2.5 (otherwise, Raw Et is used)

- _New Jet Energy Correction implemented_
- JetCorr04a
- In Jet collection, jet counted if :
- Raw Et > 10 GeV
- EmFract < 0.9
- Rjet-lepton > 0.4
- The Jet Et is corrected at L5 if  < 2.5 (otherwise, Raw Et is used)

**“****N-1 plot”**
**We apply jet and mass  requirement in events with at least 3 leptons**

- 8/01/04

## Kinematic variables: jet (II)

**TRILEPTON EVENTS**
**Jet multiplicity in events with at least 3 leptons with INVARIANT MASS CUT applied. The third object is either a real lepton or a fake lepton **

- 8/01/04

## Jet Multiplicity (I)

- 8/01/04

## Jet Multiplicity (II)

- 8/01/04

## MEt is corrected for:
muons (the energy in the calorimeter is substracted and the pt is added to the raw Met – Met[1] in Stntuple)
jets (any jet with EmFract<0.9 and  < 2.5 corrected)
Dilepton region, energy of the muon addition of Had and Em energy 
Trilepton region, assume the average deposit of energy 2.5 GeV 

- MEt is corrected for:
- muons (the energy in the calorimeter is substracted and the pt is added to the raw Met – Met[1] in Stntuple)
- jets (any jet with EmFract<0.9 and  < 2.5 corrected)
- Dilepton region, energy of the muon addition of Had and Em energy
- Trilepton region, assume the average deposit of energy 2.5 GeV

- 8/01/04

## Control regions for the trilepton analysis

**Background normalized to 346 pb****-1**

**Control regions for the trilepton analysis**

- 8/01/04

## Jet clean up cut

| CR | A | G
 | I | E | A2 | F | H | J |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| DY | 43 | 618 | 3045 | 86 | 3 | 9 | 10 | 37 |
| Data | 86 | 649 | 2937 | 121 | 9 | 7 | 15 | 29 |

| CR | A | G
 | I | E | A2 | F | A2 | F |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| DY | 33 | 546 | 2692 | 65 | 2 | 7 | 8 | 29 |
| Data | 63 | 563 | 2530 | 77 | 8 | 6 | 10 | 21 |

**If the events with at least one jet at ********<1 or at least one jet in the chimney are removed**

- 8/01/04

## Invariant mass (I)

- Dimuon Event

- Mass and Jet cut applied

**Invariant mass (I)**

- 8/01/04

## Invariant mass (II)

- CR A2

- CR Z mass window

- 8/01/04

## Corrected Met (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

## Corrected Met (II)

- CR A2

- CR Z mass window

- 8/01/04

## Raw Met (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

## Raw Met (II)

- CR A2

- CR Z mass window

**Raw Met (II)**

- 8/01/04

##  between muons (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

##  between muons (II)

- CR A2

- CR Z mass window

- 8/01/04

## Jet  (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

## Jet  (II)

- 8/01/04

## Pt leading muon (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

## Pt leading muon (II)

- CR A2

- CR Z mass window

- 8/01/04

## Pt non leading muon (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

## Pt non leading muon (II)

- CR Z mass window

**Pt non leading muon (II)**

- 8/01/04

##  between leading muon and Met (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

##  between leading muon and Met (II)

- CR A2

- CR Z mass window

- 8/01/04

##  between non leading muon and Met (I)

- Dimuon Event

- Mass and Jet cut applied

- 8/01/04

##  between non leading muon and Met (II)

- CR A2

- CR Z mass window

- 8/01/04

## Low Met control regions

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 2692 | 0.06+0.03 | 0.002 | 2692 | 2530 |

**Control region I: nJet<=1  **

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 29 | 0+0.002 | 0.006 | 29 | 21 |

**Control region J: nJet>=2**

**NON Z mass region****  **

- 8/01/04

## Low Met control regions

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 546 | 0.13+0.02 | 0.004 | 546 | 563 |

**Control region G: nJet<=1  **

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 8 | 0.01+0.001 | 0.04 | 8 | 10 |

**Control region H: nJet>=2**

**Z mass region****  **

- 8/01/04

## High Met control regions

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 33 | 3+0.47 | 0.31 | 37 | 63 |

**Control region A: nJet<=1  **

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 2 | 0.05+0.015 | 1.2 | 3 | 8 |

**Control region A2: nJet>=2**

**NON Z mass region****  **

- 8/01/04

## High Met control regions

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 65 | 0.65+0.56 | 0.1 | 66 | 77 |

**Control region E: nJet<=1  **

| DY
 | WW+WZ | t-tbar | Total Expect. | Data |
| --- | --- | --- | --- | --- |
| 7 | 0.02+0.02 | 0.28 | 7 | 6 |

**Control region F: nJet>=2**

**Z mass region****  **

- 8/01/04

## Large discrepancy in the high MEt regions
Disagreement seems to improve when using BcPt
Disagreement present in the old data also (version6 of Good Run List)
Problem is spotted by other independent groups
Looks unrelated to the tracking resolution since cutting on separation between muons and MEt doesn’t improve the agreement
See better agreement when running on data veto-ing events with more than 1 vertex; running now on new ntuple with the correct ZVertexBlock

- Large discrepancy in the high MEt regions
- Disagreement seems to improve when using BcPt
- Disagreement present in the old data also (version6 of Good Run List)
- Problem is spotted by other independent groups
- Looks unrelated to the tracking resolution since cutting on separation between muons and MEt doesn’t improve the agreement
- See better agreement when running on data veto-ing events with more than 1 vertex; running now on new ntuple with the correct ZVertexBlock

- 8/01/04

## Solve the discrepancy at large MET
Chris Hays and David Waters suggest re-weight based on MET 
Stephan suggests further investigation splitting the events into events with MET aligned to muons and MET randomly distributed
Calculate the fake rate for CMIO muons to cross check Liverpool results: use new cut for isolation at low pt (tot iso < 2 GeV)?
Evaluate the heavy flavor contribution
Calculate the systematics
Lepton Energy scale
Lepton ID SF
Jet Energy resolution
ISR/FSR for signal and backgrounds (samples ?)
Luminosity
Fake rate
Conversion removal due to material 

- Solve the discrepancy at large MET
- Chris Hays and David Waters suggest re-weight based on MET
- Stephan suggests further investigation splitting the events into events with MET aligned to muons and MET randomly distributed
- Calculate the fake rate for CMIO muons to cross check Liverpool results: use new cut for isolation at low pt (tot iso < 2 GeV)?
- Evaluate the heavy flavor contribution
- Calculate the systematics
- Lepton Energy scale
- Lepton ID SF
- Jet Energy resolution
- ISR/FSR for signal and backgrounds (samples ?)
- Luminosity
- Fake rate
- Conversion removal due to material

- 8/01/04

## MEt components 

**Region A (dilepton region outside Z, nJets<=1 and MEtv > 15 GeV **

**Data**
**Drell Yan**

**Data**
**Drell Yan**

- 8/01/04

## March 17th STATUS REPORT
March 24th UNBLINDING APPROVAL
March 31st PREBLESSING 
April 14th BLESSING

APS week from April 16th 

- March 17th STATUS REPORT
- March 24th UNBLINDING APPROVAL
- March 31st PREBLESSING
- April 14th BLESSING
- APS week from April 16th

- 8/01/04

## Back up slides

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## DataSet validation

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## Slide 51

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## Slide 52

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## Fake rate calculation

**The fakeable object is used as third lepton in the event; the event goes through the analysis cuts with a weight = f.r. **

**Fake rate calculation**

**DEFINITION  (object based)**
**probability of a given jet/track to fake an electron/muon**

**CALCULATION**

- 8/01/04

## ID Cuts for low pT muons

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## Dimuon event

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## Slide 56

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## Z mass region

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## Slide 58

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## Step2: Mass and Jet cuts applied

- 8/01/04

## Slide 60

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