JetParton matcher for the ATLAS SUSY RPV Multijet analysis

Dependencies

• Python3.8+
• External python modules: ROOT

How does it work?

The RPVMatcher class matches jets to last quarks in the gluino decay chain (and optionally FSRs).

NOTES:

• Jets must have been selected already (any kinematic/quality cut or of any other kind must have been applied already).
• When FSRs are provided, first jets are tried to be matched to the particles provided as partons, then non-matched jets are tried to be matched to FSRs not associated to already matched particles.
• The matching procedure is decided through the MatchingCriteria property which states if DeltaR values are recomputed or if FT decisions are used instead.

Inputs:

Three types of inputs are supported:

• Jets: jets are provided as a list of RPVJet objects
• Last quarks in the gluino decay chain are provided as a list of RPVParton objects
• FSRs are provided as a list of RPVParton objects

Inputs can be provided during initialization:

matcher = RPVMatcher(Jets = selected_jets, Partons = partons, [FSRs = fsrs])

or can be added using the appropriate methods:

add_jets(self, jets: [RPVJet])
add_partons(self, partons: [RPVParton])
add_fsrs(self, fsrs: [RPVParton])

Properties:

The following properties can be set through the set_property() method:

• "ReturnOnlyMatched" (value type: bool): set to True to return only matched jets (False by default)
• "MatchingCriteria" (value type: str): there are currently three options: 'UseFTDeltaRvalues', 'RecomputeDeltaRvalues_drPriority' and 'RecomputeDeltaRvalues_ptPriority' (RecomputeDeltaRvalues_drPriority by default):
  • 'RecomputeDeltaRvalues_drPriority': When using FSRs, if two jet-FSR pairs are associated to the same last quark in chain, the jet-FSR pair with lowest DeltaR value is chosen
  • 'RecomputeDeltaRvalues_ptPriority': When using FSRs, if two jet-FSR paris are associated to the same last quark in chain, the jet-FSR pair having the largest jet pt is chosen
• "DeltaRcut" (value type: float): maximum DeltaR value cut used for matching jets to partons when 'MatchingCriteria' == 'RecomputeDeltaRvalues' (0.4 by default)
• "Debug" (value type: bool): enable higher verbosity (False by default)

How to prepare jets?

A list of RPVJet objects must be created. Each jet (instance of RPVJet) must call SetPtEtaPhiE() to set the jet's kinematics.

In addition, if "MatchingCriteria" is set to "UseFTDeltaRvalues" the corresponding methods need to be called (set_matched_parton_barcode() for partons and set_matched_fsr_barcode() for FSRs).

How to prepare partons (last quark in the gluino decay chain)?

A list of RPVParton objects must be created. Each parton (instance of RPVParton) must call SetPtEtaPhiE() to set the parton's kinematics.

In addition, if "MatchingCriteria" is set to "UseFTDeltaRvalues" the following methods need to be called:

set_gluino_barcode()
set_barcode()
set_pdgid()

How to prepare FSRs?

A list of RPVParton objects must be created. Each FSR (instance of RPVParton) must call SetPtEtaPhiE() to set the FSR's kinematics.

In addition, if "MatchingCriteria" is set to "UseFTDeltaRvalues" the following methods need to be called:

set_quark_barcode() # barcode of corresponding parton from the same gluino decay chain
set_gluino_barcode()
set_barcode()
set_pdgid()

How to run?

Run the match() method of RPVMatcher which will retrieve jets decorated with all the relevant information.

The following methods can be called after jets are matched:

is_matched()
get_match_type() # will return "Parton" or "FSR" if matched and "None" if not
get_match_barcode()
get_match_parton_index()
get_match_pdgid()
get_match_barcode()
get_match_gluino_barcode()

Example

An example can be found in the repository as example.py

For developers

Please run python -m pytest for testing your local changes. If changes on the references are observed and understood, update reference files with update_references.py.

UML Sequence Diagram for the case MatchingCriteria == 'RecomputeDeltaRvalues_drPriority'