MCUtils.h

Go to the documentation of this file.

// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
 
#ifndef O2_MCUTILS_H
#define O2_MCUTILS_H
 
#include <string>
#include <SimulationDataFormat/MCTrack.h>
#include <SimulationDataFormat/ParticleStatus.h>
#include "TPDGCode.h"
#include "TParticle.h"
 
namespace o2
{
namespace mcutils
{
 
class MCTrackNavigator
{
 public:
  static bool isPhysicalPrimary(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  static bool isKeepPhysics(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
  static bool isFromPrimaryDecayChain(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  // some convenience functions for navigation
 
  static o2::MCTrack const& getFirstPrimary(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  static o2::MCTrack const* getMother(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  static o2::MCTrack const* getDaughter(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  static o2::MCTrack const* getDaughter0(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
  static o2::MCTrack const* getDaughter1(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
  // static void getParentChain(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer, std::vector<o2::MCTrack> &ancestorchain);
 
 
  ClassDefNV(MCTrackNavigator, 1);
};
 
class MCGenHelper
{
 public:
  // Helper function for users which takes over encoding of status code as well as (re-)setting correct transport bit.
  // Has to be in a class as a static methid. Just in a namespace it doesn't work to use this function in ROOT macros.
  static void encodeParticleStatusAndTracking(TParticle& particle, bool wanttracking = true);
  static void encodeParticleStatusAndTracking(TParticle& particle, int hepmcStatus, int genStatus, bool wanttracking = true);
  ClassDefNV(MCGenHelper, 1)
};
 
inline bool isStable(int pdg)
{
  //
  // Decide whether particle (pdg) is stable
  //
 
  // All ions/nucleons are considered as stable
  // Nuclear code is 10LZZZAAAI
  if (pdg > 1000000000) {
    return true;
  }
 
  const int kNstable = 18;
  int pdgStable[kNstable] = {
    kGamma,      // Photon
    kElectron,   // Electron
    kMuonPlus,   // Muon
    kPiPlus,     // Pion
    kKPlus,      // Kaon
    kK0Short,    // K0s
    kK0Long,     // K0l
    kProton,     // Proton
    kNeutron,    // Neutron
    kLambda0,    // Lambda_0
    kSigmaMinus, // Sigma Minus
    kSigmaPlus,  // Sigma Plus
    3312,        // Xsi Minus
    3322,        // Xsi
    3334,        // Omega
    kNuE,        // Electron Neutrino
    kNuMu,       // Muon Neutrino
    kNuTau       // Tau Neutrino
  };
 
  // this is linear search ---> a hash map or binary search should be more appropriate??
  for (int i = 0; i < kNstable; ++i) {
    if (pdg == std::abs(pdgStable[i])) {
      return true;
    }
  }
  return false;
}
 
} // namespace mcutils
} // namespace o2
 
#endif // O2_MCUTILS_H