B2A303-MultipleDecays-Reconstruction.py

#!/usr/bin/env python3
 
 
 
 
 
import basf2 as b2
import modularAnalysis as ma
import variables.collections as vc
import variables.utils as vu
 
# create path
my_path = b2.create_path()
 
# load input ROOT file
ma.inputMdst(environmentType='default',
             filename=b2.find_file('B2pi0D_D2hh_D2hhh_B2munu.root', 'examples', False),
             path=my_path)
 
# create and fill final state ParticleLists
kaons = ('K-', '')
pions = ('pi-', '')
photons = ('gamma', '')
ma.fillParticleListsFromMC(decayStringsWithCuts=[kaons, pions, photons],
                           path=my_path)
 
# 1. reconstruct pi0 -> gamma gamma decay
# InvM is the sum of daughter momenta whereas M is the initialised PDG mass ...
ma.reconstructDecay(decayString='pi0 -> gamma gamma',
                    cut='0.1 < InvM < 0.15',
                    path=my_path)
 
# 2. reconstruct D0 in multiple decay modes
ma.reconstructDecay(decayString='D0:ch1 -> K- pi+',
                    cut='1.8 < M < 1.9',
                    dmID=1,
                    path=my_path)
ma.reconstructDecay(decayString='D0:ch2 -> K- pi+ pi0',
                    cut='1.8 < M < 1.9',
                    dmID=2,
                    path=my_path)
ma.reconstructDecay(decayString='D0:ch3 -> K- pi+ pi+ pi-',
                    cut='1.8 < M < 1.9',
                    dmID=3,
                    path=my_path)
ma.reconstructDecay(decayString='D0:ch4 -> K- K+',
                    cut='1.8 < M < 1.9',
                    dmID=4,
                    path=my_path)
ma.reconstructDecay(decayString='D0:ch5 -> pi+ pi-',
                    cut='1.8 < M < 1.9',
                    dmID=5,
                    path=my_path)
 
# merge the D0 lists together into one single list
ma.copyLists(outputListName='D0:all',
             inputListNames=['D0:ch1', 'D0:ch2', 'D0:ch3', 'D0:ch4', 'D0:ch5'],
             path=my_path)
 
# 3. reconstruct B+ -> anti-D0 pi+ decay
ma.reconstructDecay(decayString='B+:D0pi -> anti-D0:all pi+',
                    cut='5.24 < Mbc < 5.29 and abs(deltaE) < 1.0',
                    dmID=1,
                    path=my_path)
 
# perform MC matching (MC truth association)
ma.matchMCTruth(list_name='B+:D0pi',
                path=my_path)
 
# Select variables that we want to store to ntuple
d_vars = vc.inv_mass + vc.kinematics
pi_vars = vc.kinematics
b_vars = vc.deltae_mbc + \
    vc.mc_truth + \
    vu.create_aliases_for_selected(list_of_variables=d_vars,
                                   decay_string='B+ -> ^anti-D0 pi+',
                                   prefix='D0') + \
    vu.create_aliases_for_selected(list_of_variables=pi_vars,
                                   decay_string='B+ -> anti-D0 ^pi+',
                                   prefix='pi') + \
    vu.create_aliases(list_of_variables=['decayModeID'],
                      wrapper='daughter(0,extraInfo({variable}))',
                      prefix="")
 
# Saving variables to ntuple
output_file = 'B2A303-MultipleDecays-Reconstruction.root'
ma.variablesToNtuple(decayString='B+:D0pi',
                     variables=b_vars,
                     filename=output_file,
                     treename='bp',
                     path=my_path)
 
 
# Process the events
b2.process(my_path)
 
# print out the summary
print(b2.statistics)