Filtered MC sample for the pi0 and eta Dalitz decay

Description

Large sample to fix the shape of the fit to the MC sample in the data fit. @mwilkins requested those in the past, as shown in lhcb-datapkg/WG/ExoticaConfig!34 (diffs) , however the sample size is quite low in some regions of the phase-space by binning in bins of 5MeV. Since the good mee resolution in Run 3 (3-5MeV) allows us to bin in half of the resolution, meaning 1.5-2.5MeV, because of which we need to have a significantly large sample.

Because of the need of this large MC sample, only the Block 7 sample is requested. Sample differences evaluated with smaller samples.

Retention rate calculation The retention rate from the simulation webpage https://twiki.cern.ch/twiki/bin/viewauth/LHCbPhysics/FilteredSimulationProduction is

fevolle@lxplus960:~$ lb-dirac dirac-bookkeeping-rejection-stats -B /MC/2024/Beam6800GeV-2024.W40.41-MagDown-Nu7.6-25ns-Pythia8/Sim10f/HLT2-2024.W40.42/39122948/HLT2.DST
Using BK query {'ConfigName': 'MC', 'ConfigVersion': '2024', 'ConditionDescription': 'Beam6800GeV-2024.W40.41-MagDown-Nu7.6-25ns-Pythia8', 'ProcessingPass': '/Sim10f/HLT2-2024.W40.42', 'EventType': '39122948', 'FileType': 'HLT2.DST', 'Visible': 'Yes', 'SimulationConditions': 'Beam6800GeV-2024.W40.41-MagDown-Nu7.6-25ns-Pythia8', 'ReplicaFlag': 'Yes'}
Checking if BK EventInputStat is reliable... Found 89 top files
: OK in 6.5 seconds
Getting metadata for 87 files  : completed in 0.1 seconds
Getting metadata for 86 jobs : completed in 0.1 seconds
Event stat: 1032389 on 87 files
EventInputStat: 1032389 from 87 jobs
Retention: 100.00 %
fevolle@lxplus960:~$ lb-dirac dirac-bookkeeping-rejection-stats -B /MC/2024/Beam6800GeV-2024.W41.42-MagUp-Nu7.6-25ns-Pythia8/Sim10f/HLT2-2024.W40.42/39122948/HLT2.DST
Using BK query {'ConfigName': 'MC', 'ConfigVersion': '2024', 'ConditionDescription': 'Beam6800GeV-2024.W41.42-MagUp-Nu7.6-25ns-Pythia8', 'ProcessingPass': '/Sim10f/HLT2-2024.W40.42', 'EventType': '39122948', 'FileType': 'HLT2.DST', 'Visible': 'Yes', 'SimulationConditions': 'Beam6800GeV-2024.W41.42-MagUp-Nu7.6-25ns-Pythia8', 'ReplicaFlag': 'Yes'}
Checking if BK EventInputStat is reliable... Found 83 top files
: OK in 3.6 seconds
Getting metadata for 86 files  : completed in 0.1 seconds
Getting metadata for 85 jobs : completed in 0.1 seconds
Event stat: 1018248 on 86 files
EventInputStat: 1018249 from 86 jobs
Retention: 100.00 %

This seem definitely not include the HLT1 filtering. Therefore calculating :

retention rate = entries in the MCDecayTree / entries in DecayTree after HLT1 + HLT2 
retention rate pi0 Dalitz = 13381.0/3154957 = 0.00424 
retention rate eta Dalitz = 17423.0/1415585 = 0.0123