vertexDisplacer.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
 
 
 
from basf2 import *
from simulation import add_simulation
from reconstruction import add_reconstruction, add_mdst_output
from ROOT import Belle2
import modularAnalysis as ma
 
main = create_path()
 
eventinfosetter = main.add_module("EventInfoSetter", evtNumList=[100], expList=[1003])
 
# Generate decay with your favourite generator, using EvtGen as example
# the decay file should include the particle(s) to be displaced
dec_file = None
if len(sys.argv) > 1:
    dec_file = os.path.abspath(sys.argv[1])
    print("using following decay file: " + dec_file)
 
main.add_module('EvtGenInput', ParentParticle='Upsilon(4S)', userDECFile=dec_file)
 
# initialise the displacer module
displacer = register_module("GeneratedVertexDisplacer")
 
# list of pdg values for particles to be displaced, here 100
displacer.param("pdgVal", (100))
 
# list of lifetimes corresponding to the particles to be displaced, here c*tau = 10cm
displacer.param("lifetime", (10))
# pass the lifetime in units of [ns]: displacer.param("ctau", False)
 
# specifying exponential decay option
displacer.param("lifetimeOption", "exponential")
 
# add displacer module between generator and detector simulation
main.add_module(displacer)
 
# print the MC particles for verification
ma.printMCParticles(onlyPrimaries=False, maxLevel=-1, path=main)
 
# detector simulation
add_simulation(main)
 
# reconstruction
add_reconstruction(main)
 
# save to file
add_mdst_output(main, filename='displacerOut.root')
 
process(main)