participant_spectator_model.h

#ifndef PARTICIPANT_SPECTATOR_MODEL_H
#define PARTICIPANT_SPECTATOR_MODEL_H
 
#include "KVNucleus.h"
 
namespace KVImpactParameters {
   class participant_spectator_model {
      double A1, A2, Z1, Z2, R1, R2, _beta, NORM;
      int sector(double BETA, double NU) const;
 
      enum Sector
      { I = 1, II, III, IV };
 
   public:
      participant_spectator_model() {}
      participant_spectator_model(const KVNucleus& PROJ, const KVNucleus& TARG, Bool_t normalize_b = kFALSE, Bool_t normalize_participants = kFALSE)
         : A1(PROJ.GetA()), A2(TARG.GetA()),
           Z1(PROJ.GetZ()), Z2(TARG.GetZ()),
           R1(1.2 * pow(PROJ.GetA(), 1. / 3.)),
           R2(1.2 * pow(TARG.GetA(), 1. / 3.)),
           _beta(1. / (R1 + R2))
      {
 
         if (normalize_b) _beta = 1;
         if (normalize_participants) NORM = total_participants(0);
         else NORM = 1;
      }
      virtual ~participant_spectator_model() {}
 
      void set(const KVNucleus& PROJ, const KVNucleus& TARG, Bool_t normalize_b = kFALSE, Bool_t normalize_participants = kFALSE)
      {
         A1 = PROJ.GetA();
         A2 = TARG.GetA();
         Z1 = PROJ.GetZ();
         Z2 = TARG.GetZ();
         R1 = 1.2 * pow(PROJ.GetA(), 1. / 3.);
         R2 = 1.2 * pow(TARG.GetA(), 1. / 3.);
         _beta = 1. / (R1 + R2);
         if (normalize_b) _beta = 1;
         if (normalize_participants) NORM = total_participants(0);
         else NORM = 1;
      }
      double  F(double b, bool target = false) const;
      double operator()(double* x, double*)
      {
 
         return total_participants(*x) / NORM;
      }
      double total_participants(double b) const
      {
 
         return (projectile_participants(b) + target_participants(b));
      }
      double projectile_participants(double b) const
      {
         return A1 * F(b);
      }
      double target_participants(double b) const
      {
         return A2 * F(b, true);
      }
      double proton_participants(double b) const
      {
         return (Z1 / A1) * projectile_participants(b) + (Z2 / A2) * target_participants(b);
      }
 
      ClassDef(participant_spectator_model, 0)
   };
 
}
 
#endif // PARTICIPANT_SPECTATOR_MODEL_H