#!/usr/bin/env bash
#

# This is a simple simulation example showing how to force a specific particle decay chain.
# To simplify the example, we will use a Box generator to inject Lambda0 particles in the simulation.
#
# What we want to achieve is a forced decay chain of the Lambda0
# Lambda0 --> n pi0 --> n e+ e- gamma
#
# Given that both the Lambda0 and the pi0 are by default decayed by Geant, we have to turn on the external decayer for these particles.
# This can be done with
# --configKeyValues 'SimUserDecay.pdg=3122 111'
#
# On top of that we have to setup the external decayer to perform the decay forcing the channels we desire.
# The default external decayer configuration is loaded from
# ${O2_ROOT}/share/Generators/pythia8/decays/base.cfg
# which is assigned to the slot #0 of the configuration parameter 'DecayerPythia8.config'.
#
# What we want to do is to add on top of the default configuration some extra settings that are provided in the `decay_lambda_neutron_dalitz.cfg` file.
# This can be done with
# --configKeyValues 'DecayerPythia8.config[1]=decay_lambda_neutron_dalitz.cfg'
#

set -x

NEV=10
o2-sim -j 20 -n ${NEV} -g boxgen -m PIPE ITS TPC --configKeyValues 'BoxGun.pdg=3122;BoxGun.number=1;SimUserDecay.pdglist=3122 111;DecayerPythia8.config[1]=decay_lambda_neutron_dalitz.cfg;DecayerPythia8.verbose=true'
