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The SUSY PAT in the Jet MET Tau Final State (Status Update)

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(Status Update) Jonathan Asaadi, Alfredo Gurrola, Seema Sharma*, Teruki Kamon, and David Toback All Hadronic SUSY Group Meeting Texas A&M *Tata Institute – PowerPoint PPT presentation

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Title: The SUSY PAT in the Jet MET Tau Final State (Status Update)


1
The SUSY PAT in the JetMETTau Final
State (Status Update)
  • Jonathan Asaadi, Alfredo Gurrola, Seema Sharma,
  • Teruki Kamon, and David Toback
  • All Hadronic SUSY Group Meeting
  • Texas AM
  • Tata Institute
  • 10/16/08

2
Goals of the SUSY PAT w/ Taus
  • Implement PATTau Information into the SUSY PAT
  • Allow search for SUSY High Tan(b) where Taus are
    in the final state
  • Do this is a standard way similar to
    PATElectrons, PATMuonsetc
  • Understand / Validate Tau information found in
    the PAT
  • Evaluate how well the default PAT settings
    identify Taus by comparing to Monte Carlo Truth
    (establish efficiencies)
  • Determine what additional discriminators should
    be added to identify good tau candidates
  • Write an event selector for the SUSY PAT that
    selects events based on Tau criteria
  • Allow the study of SUSY event topology with Jet
    MET Taus using a standard set of tools

3
Outline
  • Understanding PATTau objects
  • (The way it is)
  • Diagram of PATTau definition
  • Plots of Tau variables accessed in the SUSY PAT
  • Tau Event Selector in SUSY PAT
  • (What weve done so far)
  • Using what is in the PAT now
  • Attempting to reproducing the CMS TDR results
  • Method used by ElectroWeak Tau group
  • The Next Steps for the Tau Event Selector in the
    SUSY PAT
  • (Where we are going)
  • Conclusions

4
Basic Structure of PATTau in CMSSW_1_6_12
ECAL and HCAL and Tracking information is
used with Particle Flow Algorithm to generate a
list of Particle Flow Candidates (Particle Flow
Block) Now apply an Iterative Cone Algorithm and
clustering to develop a list of Particle Flow
Jets
Event Information
Particle Flow Jets
Important Variables Contained in PFJets Charged
Hadron Track Kinematic Variables Neutral Hadron
Track Kinematic Variables Trigger
Information Calorimeter Isolation Information
Particle Flow Taus
PATTaus
5
Basic Structure of PATTau in CMSSW_1_6_12
Event Information
Information from the PFJet list is taken and
track and isolation requirements are applied to
construct PF Tau list Additional Monte Carlo
Matching and cross cleaning can be done at this
level
Particle Flow Jets
Particle Flow Taus
Important Variables Contained in PFTaus - Lead
Charged Hadron Track Pt gt 5 GeV - Maximum Lead
Charged Hadron Track Impact Parameter lt 0.2 -
Monte Carlo Matching Cone DR 0.6 - ECAL, HCAL,
and Tracker Signal Cone DR 0.6 - ECAL, HCAL,
and Tracker Isolation Cone DR 0.6 - Standard
Particle Kinematic Information
PATTaus
Note Since the Signal Cone and Isolation Cone
are the same size by default
6
Basic Structure of PATTau in CMSSW_1_6_12
Event Information
PAT Layer 0 - Performs basic cleaning 1)
PFTauDiscriminationByIsolation - of other
charged Hadrons in Tracker Isolation Annulus
0 - of other charged Hadrons in ECAL Isolation
Annulus 0 2) Overlap Checking to remove
Electrons and Muons in some DR 0.5 off by
default
Particle Flow Jets
Particle Flow Taus
PAT Layer 1 - Breaks Layer 0 into types
patLepton and object inherits Layer 0
information from the source (recoPFTau) -
Performs matching with trigger Primitives
(tauTrigMatchHLT1Tau) - Adds Layer 1 Isolation
Information (tracker, ECal, and HCal
Isolation) PAT does not cut on this isolation
information by default - Adds PAT Variables
(emEnergyFraction, eOverP, leadeOverP)
PATTaus
SUSY PAT
7
Tau Event Selector
  • What we found was that patTau in version PAT
    1_6_12 was a list of PFJets that pass
    discrimination by isolation requirement
  • PFRecoTauDiscriminationByIsolation is set by
    default to pass all PFJets
  • Monte Carlo Matching is turned off by default

Produced for LM2 SUSY Point
High Pt Tau is a PFjet
Shown Previously
High Tau Multiplicity
Shown Previously
8
Monte Carlo Truth Plots
  • We are working on generating Monte Carlo matching
    for these plots
  • Matching PATTaus to reco PFTaus from which they
    are constructed, and than matching that to Monte
    Carlo particles proves to be a tricky task!
  • This process is underway and will have more to
    say on this in the upcoming slides

9
Tau Event Selector (Version 1.0)
  • We needed to add stronger selection criteria to
    the PATTaus in order to study SUSY produced
    taus in the PAT
  • Want to do this in the same way others are
    proceeding
  • Wanted to make this configurable to the user yet
    done in the standard way
  • Obtained code used for the Electroweak Tau
    analysis and modified it for use in the SUSY PAT
    Tau framework
  • Added Isolation parameters based on Particle Flow
    requirements
  • Additionally added Track multiplicity information
    and Lead Track Pt requirements

10
Tau Event Selector (Version 1.0)
  • Tau Event Selector now takes patTaus and
    matches them to their particle flow candidate
  • Then takes an Inner Isolation Cone and an Outer
    Isolation Cone Size to be configured by user
  • Then applies an Isolation Minimum and Isolation
    Maximum cut values to be configured by user
    based on other charged hadronic candidates Pt in
    the isolation cone
  • If the candidate passes this Particle Flow
    Isolation requirement then the user can select
    the event based on other selection criteria(see
    next slide)

11
Tau Event Selector (Version 1.0)
  • A glimpse at the code
  • OuterIsolationConeSize 0.5
  • InnerIsolationConeSize 0.05
  • IsolationMinCut 0.0
  • IsolationMaxCut 10.0
  • minPtTau 20.,20.
  • maxEtaTau 2.2,2.2
  • minNumberTrackTau 1.0,1.0
  • minLeadTrackPt 5.0, 5.0
  • minTrackIsoTau 0, 0 Note Set to zero until
    variable is better understood

Particle Flow Isolation Variables
Tau Kinematic Variables
12
Tau Event Selector (Version 1.0) Results
SUSY PAT w/Tau 34,000 Signal Events -gt Selected
1901 Events 5.6 of events selected
Number of Taus
Tau Selection After Isolation Number of Taus gt
2 Minimum Pt of Each Tau gt 20 GeV Maximum Eta of
Each Tau lt 2.2 Minimum Number of Tracks
1 Minimum Pt of Lead Track 5 GeV
Excess in 1 and 3 Prong Tracks !
Number of Signal Tracks
Tau Pt
13
Tau Event Selector (Version 1.0) Results
SUSY PAT w/Tau 34,000 Signal Events -gt Selected
1901 Events 5.6 of events selected
Opposite Sign Di-Tau Invariant Mass
Like Sign Di-Tau Invariant Mass
Opposite Sign Di-Tau Invariant Mass
Lead Track Pt
We need MC matching to evaluate exactly how well
these selection criteria do This is in progress
14
Using Tau Event Selector (Version 1.0)
  • One benchmark for performance is how well do our
    results match the CMS Technical Design Report Vol
    II results for Di-Tau mass selected from SUSY LM2
    sample

Produced for LM2 SUSY Point
Event Selection Missing Et gt 150 GeV Number of
Tau Candidates gt 2 At least 2 Jets with Et gt 150
GeV DR between any tau pair lt 2 (Not
implemented in my selection yet)
Tau Selection After Isolation Minimum Pt of Each
Tau gt 20 GeV Maximum Eta of Each Tau lt
2.2 Minimum Number of Tracks 1 Minimum Pt of
Lead Track 5 GeV Select only 1 3 Prong Taus
15
SUSY PAT w/Tau ? CMS TDR Event Selection
  • CMS TDR
  • 93,500 Signal Events -gt Selected 2735 Events
  • 2.8 of events selected
  • SUSY PAT w/Tau
  • 34,000 Signal Events -gt Selected 782 Events
  • 2.3 of events selected

Good agreement with the peak !
Opposite Sign Di-Tau Invariant Mass
Resonable Endpoint
16
SUSY PAT w/Tau ? CMS TDR Event Selection
Opposite Sign Di-Tau Invariant Mass
Like Sign Di-Tau Invariant Mass
Opposite Sign Di-Tau Invariant Mass
Like Sign Di-Tau Invariant Mass
Encouraging to see that both distributions
flatten out above 100 GeV
17
The Next Version of the Tau Event Selector in the
SUSY PAT
  • After discussions with Tau experts and looking at
    the model for selecting good taus from the
    PFTau and Electroweak tau groups we have started
    with a slightly modified method for selecting
    taus in the PAT
  • This is the same method as used by the
    Electroweak Tau group
  • Maintains the use of PATTau at the SUSY PAT
    level
  • Keeps with the standard Particle Flow definition
    for taus

18
Tau Event Selector (Version 2.0)
Event Information
Everything will proceed the same as before
through these step!
Particle Flow Jets
Particle Flow Taus
But now we will create two distributions of
Particle Flow Taus
The SUSY PAT Particle Flow Tau List (created
using our own set of standard PF discrimination
and isolation cuts)
The Default Particle Flow Tau List (created the
same as before)
User chooses which list to input to the PAT
SUSY PAT Tau Event Selector
PATTaus
19
The SUSY PAT Tau List
  • This will be a list of Particle Flow Tau
    Candidates that pass the standard Tau Id
  • Since the discrimination variables from the
    particle flow information are dropped by the PAT,
    this set-up will allow the PATTau which is
    constructed from this collection to already have
    the standard Tau Id performed
  • The exact configuration for the Tau Id variables
    will be able to be manipulated by the end user
  • This will allow Monte Carlo information to be
    stored with the collection making evaluating
    efficiencies easier at each step
  • Moreover, this will allow the SUSY PAT to
    continue to use the standard PAT objects as input
    without having to add difficult or non-standard
    methods to the selectors

20
Next Steps / Conclusions
  • We are on the path to implementing taus into the
    SUSY PAT in a standard but end-user configurable
    way
  • Working with Electroweak and Particle Flow Tau
    groups to implement the standard Tau Id
  • We are adding / analyzing the Monte Carlo
    information to establish concrete efficiencies
    for our selector
  • Need to establish the efficiency of selecting
    taus
  • Need to establish efficiency of selecting
    golden events
  • Stay Tunedmore exciting results to come!

21
BACKUP SLIDES
22
Tau Event Selector Variables
23
SUSY PAT w/Tau ? CMS TDR Event Selection
  • Allowing only 1 and 3 Prong Taus to Construct
    Invariant Mass

24
PATTau
Note Since the Signal Cone and Isolation Cone
are the same size
Track Pt Requirements
Particle Flow Reco Tau Producer Default
Setting (It is from this information that
PATTau is constructed) LeadChargedHadron_minPt
5. GeV ChargedHadrCand_minPt 1 GeV
LeadChargedHadron_trackmaxDZ
0.2 NeutralHadron_minPt 1. GeV
GammaCand_minPt 1. GeV LeadTrack_minPt 5.
GeV Track_minPt 1.
GeV TrackLeadTrack_maxDZ 0.2 MatchingConeSize_
min 0.00 MatchingConeSize_max 0.60
TrackerSignalConeSize_min 0.00
TrackerSignalConeSize_max 0.60
TrackerIsolConeSize_min 0.00
TrackerIsolConeSize_max 0.60 ECALSignalConeSiz
e_min 0.00 ECALSignalConeSize_max 0.60
ECALIsolConeSize_min 0.00
ECALIsolConeSize_max 0.60 HCALSignalConeSize_
min 0.00 HCALSignalConeSize_max 0.60
HCALIsolConeSize_min 0.00
HCALIsolConeSize_max 0.60
Isolation Information
25
PATTau
Note Since the Signal Cone and Isolation Cone
are the same size, the isolation
annulus has size zeromaking this cut
ineffective
recoBaseTau
PAT Layer 0 - Performs basic cleaning 1)
PFTauDiscriminationByIsolation - of other
charged Hadrons in Tracker Isolation Annulus
0 - of other charged Hadrons in ECAL
Isolation Annulus 0 2) Overlap Checking to
remove Electrons and Muons in some DR 0.5
off by default - Monte Carlo Matching off by
default
PAT Layer 1 - Breaks Layer 0 into types
patLepton and object inherits Layer 0
information from the source (recoCaloTau or
recoPFTau) - Performs matching with trigger
Primitives (tauTrigMatchHLT1Tau) - Adds Layer 1
Isolation Information (tracker, ECal, and HCal
Isolation) PAT does not cut on this isolation
information by default - Adds PAT Variables
(emEnergyFraction, eOverP, leadeOverP)
patTau
SUSYPAT TauEventSelector
26
Tau Event Selector
  • We needed to add stronger selection criteria to
    the in order to study Taus in the SUSY PAT
  • Wanted to make this configurable to the user yet
    done in the standard way
  • We wrote a Tau Event Selector that would select
    good Taus
  • Added Isolation parameters based on Particle Flow
    requirements
  • Obtained code used for the Electroweak Tau
    analysis and modified it for use in the SUSY PAT
    Tau framework
  • Additionally added Track multiplicity information
    and Lead Track Pt requirements
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