B2A411-HelixErrorScaler.py

#!/usr/bin/env python3
 
 
 
 
 
import basf2 as b2
import modularAnalysis as ma
from vertex import kFit
from stdCharged import stdMu
from stdV0s import stdKshorts, scaleErrorKshorts
import variables.collections as vc
import variables.utils as vu
 
# create path
my_path = b2.create_path()
 
# load input ROOT file
ma.inputMdst(filename=b2.find_file('B02JpsiKs_Jpsi2mumu_Ks2pipi.root', 'examples', False),
             path=my_path)
 
# load standard mu and K_S0 particle lists
stdMu('loose', path=my_path)
stdKshorts(path=my_path)
 
# create a new list of mu and K_S0 with scaled error
ma.scaleError('mu+:scaled', 'mu+:loose', path=my_path)
scaleErrorKshorts(path=my_path)
 
# reconstruct B0 -> J/psi K_S0 decay
ma.reconstructDecay('J/psi:default -> mu+:loose mu-:loose', '3.05 < M < 3.15', path=my_path)
ma.reconstructDecay('B0:default -> J/psi:default K_S0:merged', '5.27 < Mbc < 5.29 and abs(deltaE)<0.1', path=my_path)
ma.reconstructDecay('J/psi:scaled -> mu+:scaled mu-:scaled', '3.05 < M < 3.15', path=my_path)
ma.reconstructDecay('B0:scaled -> J/psi:scaled K_S0:scaled', '5.27 < Mbc < 5.29 and abs(deltaE)<0.1', path=my_path)
 
# perform B0 vertex fit only using the muons
kFit('B0:default', 0., decay_string='B0 -> [J/psi -> ^mu+ ^mu-] K_S0', path=my_path)
kFit('B0:scaled', 0., decay_string='B0 -> [J/psi -> ^mu+ ^mu-] K_S0', path=my_path)
 
# MC matching
ma.matchMCTruth('B0:default', path=my_path)
ma.matchMCTruth('B0:scaled', path=my_path)
 
# select variables to be saved
B0_vars = vc.mc_truth + vc.vertex + vc.mc_vertex
B0_vars += ['LBoost', 'LBoostErr', 'mcLBoost']
helices = [a + b for a in ['d0', 'phi0', 'omega', 'z0', 'tanLambda'] for b in ['', 'Err', 'Pull']]
B0_vars += vu.create_aliases_for_selected(helices, 'B0 -> [J/psi -> ^mu+ ^mu-] [K_S0 -> ^pi+ ^pi-]')
B0_vars += vu.create_aliases_for_selected(['isFromV0'], 'B0 -> J/psi ^K_S0')
 
# save variables
outputfile = 'scaleHelixError_output.root'
ma.variablesToNtuple('B0:default', B0_vars,
                     filename=outputfile, treename='B0_default', path=my_path)
ma.variablesToNtuple('B0:scaled', B0_vars,
                     filename=outputfile, treename='B0_scaled', path=my_path)
 
# process the events
b2.process(my_path)
 
# print out the summary
print(b2.statistics)