PhokharaEvtgenGenerate.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
 
"""
<header>
    <output>PhokharaEvtgenData.root</output>
    <contact>Kirill Chilikin (K.A.Chilikin@inp.nsk.su)</contact>
    <description>Generation of 25000 e+ e- -> J/psi eta_c events.</description>
</header>
"""
 
import basf2
import generators
from ROOT import Belle2
 
# Logging level.
basf2.set_log_level(basf2.LogLevel.INFO)
 
# Random seed.
basf2.set_random_seed(12345)
 
# Create the main path.
main = basf2.create_path()
 
# Event information
main.add_module("EventInfoSetter", expList=0, runList=1, evtNumList=25000)
 
# Add combination of PHOKHARA and EvtGen.
user_decay_file_name = 'generators/examples/PhokharaEvtgenDoubleCharmonium.dec'
user_decay_file = Belle2.FileSystem.findFile(user_decay_file_name)
generators.add_phokhara_evtgen_combination(
    main, ['J/psi', 'eta_c'], user_decay_file, beam_energy_spread=False)
 
# Output.
output = basf2.register_module('RootOutput')
output.param('outputFileName', 'PhokharaEvtgenData.root')
main.add_module(output)
 
# Progress.
main.add_module('Progress')
 
# Generate events.
basf2.process(main)
 
# Show call statistics.
print(basf2.statistics)