g4simulation/g4main/HepMCNodeReader.h

0001 // Tell emacs that this is a C++ source
0002 //  -*- C++ -*-.
0003 #ifndef G4MAIN_HEPMCNODEREADER_H
0004 #define G4MAIN_HEPMCNODEREADER_H
0005
0006 #include <TF1.h>
0007
0008 #include <fun4all/SubsysReco.h>
0009
0010 // rootcint barfs with this header so we need to hide it
0011 #include <gsl/gsl_rng.h>
0012
0013 #include <string>
0014 #include <vector>
0015
0016 class PHCompositeNode;
0017
0018 //! HepMCNodeReader take input from all subevents from PHHepMCGenEventMap and send them to simulation in Geant4
0019 //! For HepMC subevent which is already simulated, they will not be simulated again in Geant4.
0020 class HepMCNodeReader : public SubsysReco
0021 {
0022  public:
0023   HepMCNodeReader(const std::string &name = "HepMCNodeReader");
0024   ~HepMCNodeReader() override;
0025
0026   int Init(PHCompositeNode *topNode) override;
0027   int process_event(PHCompositeNode *topNode) override;
0028
0029   void pythia(const bool pythia) { is_pythia = pythia; }
0030
0031   //! this function is depreciated.
0032   //! HepMCNodeReader::VertexPosition() move all HEPMC subevents to a new vertex location.
0033   //! And the vertex shifts are better controlled for individually HEPMC subevents in Fun4AllHepMCInputManagers and event generators.
0034   void VertexPosition(const double v_x, const double v_y, const double v_z);
0035
0036   //! HepMCNodeReader::SmearVertex - WARNING - this function is depreciated.
0037   //! HepMCNodeReader::SmearVertex() smear each HEPMC subevents to a new vertex location.
0038   //! And the vertex smears are better controlled for individually HEPMC subevents in Fun4AllHepMCInputManagers and event generators.
0039   //! Positive value is Gauss smear, and negative values are flat smear
0040   void SmearVertex(const double s_x, const double s_y, const double s_z);
0041
0042   //! Arbitary time shift for all sub-events.
0043   //! And the vertex shifts are better controlled for individually HEPMC subevents in Fun4AllHepMCInputManagers and event generators.
0044   void SetT0(const double t0) { vertex_t0 = t0; }
0045   //
0046   //! Override seed
0047   void SetSeed(const unsigned int i)
0048   {
0049     seed = i;
0050     use_seed = 1;
0051   }
0052
0053   // Method to add strangeness content of the event: f is the fraction of additional strangeness particles, in percent
0054   void AddStrangeness(const float f) { addfraction = f; }
0055
0056  private:
0057   double smeargauss(const double width);
0058   double smearflat(const double width);
0059
0060   // Exponentially modified Gaussian distribution function, modelling pT
0061   static double EMGFunction(double *x, double *par);
0062   // Double Gaussian function, modelling eta
0063   static double DBGFunction(double *x, double *par);
0064
0065   gsl_rng *RandomGenerator{nullptr};
0066   bool is_pythia{false};
0067   int use_seed{0};
0068   unsigned int seed{0};
0069   double vertex_pos_x{0.0};
0070   double vertex_pos_y{0.0};
0071   double vertex_pos_z{0.0};
0072   double vertex_t0{0.0};
0073   double width_vx{0.0};
0074   double width_vy{0.0};
0075   double width_vz{0.0};
0076
0077   // Method to change the strangeness content of the event
0078   std::vector<int> list_strangePID = {310, 3122, -3122};                               // K_s0 (PID=310), Lambda (PID=3122)
0079   std::vector<double> list_strangePIDprob = {1 - 0.333, 0.333 / 2., 0.333 / 2.};       // K_s0 (PID=310) has 2/3 probability, Lambda (PID=3122) has 1/3 probability
0080   std::vector<std::pair<int, std::pair<double, double>>> list_strangePID_probrange{};  // list of strange particles and their probability ranges
0081   float addfraction{0.0};                                                              // additional strangeness particles, in percent; default 0
0082   int Nstrange_add{0};                                                                 // number of strange particles to be added; default 0
0083   float sel_eta{1.0};                                                                  // |eta| selection for additional strangeness particles; default 1
0084   float sel_ptmin{0.0};                                                                // min pT selection for additional strangeness particles; default 0
0085   float sel_ptmax{std::numeric_limits<float>::max()};                                  // max pT selection for additional strangeness particles; default infinity
0086   TF1 *fpt{nullptr};
0087   TF1 *feta{nullptr};
0088 };
0089
0090 #endif