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#ifndef G4QProbability_h
#define G4QProbability_h 1
//
// $Id$
//
// ------------------------------------------------------------
// GEANT 4 class implementation file
//
// ---------------- G4QProbability ----------------
// by Mikhail Kossov Oct, 2006
// class for Pomeron & Reggeon amplitudes used by CHIPS
// For comparison similar member functions are in the G4 class:
// G4PomeronCrossSection
// ------------------------------------------------------------
// Short description: Pomeron is one of the possible vacuum pole (the
// second is Oderon, but they are identical in the present model), by
// which particle exchang in the ellastic scattering process. Others
// are Reggeons and, possibly Instantons (for spin-flip reactions).
// Strings are cuts of Pomerons and Reggeons (optic theorem connects
// the amplitude of scattering at zero angle with the total inelastic
// cross-section). They describe inelastic processes at high energies.
// ------------------------------------------------------------------
#include <CLHEP/Units/PhysicalConstants.h>
#include "globals.hh"
class G4QProbability
{
public:
G4QProbability(G4int PDGCode = 2212);
~G4QProbability(){;}
void SetS0(G4double aS0) {S0 = aS0;}
void SetPom_Gamma(G4double aPom_Gamma) {pom_Gamma = aPom_Gamma;}
void SetGamma(const G4double aGam) {pom_Gamma=aGam/CLHEP::GeV/CLHEP::GeV;}// @@ Temporary?
void SetPom_C(G4double aPom_C) {pom_C = aPom_C;}
void SetPom_R2(G4double aPom_R2) {pom_R2 = aPom_R2;}
void SetPom_Alpha(G4double aPom_Alpha) {pom_Alpha = aPom_Alpha;}
void SetPom_Alphaprime(G4double aPom_Alphaprime){pom_Alphaprime = aPom_Alphaprime;}
// Genegal (with low energies)
G4double GetQexTotProbability(const G4double s, const G4double imp2);
G4double GetQexCohProbability(const G4double s, const G4double imp2);
G4double GetQexDiffProbability(const G4double s, const G4double imp2);
G4double GetQexDubDiffProbability(const G4double s, const G4double imp2);
G4double GetQexSinDiffProbability(const G4double s, const G4double imp2);//For each T & B
G4double GetQexAbsProbability(const G4double s, const G4double imp2);
G4double GetQexElProbability(const G4double s, const G4double imp2);
G4double GetQexInelProbability(const G4double s, const G4double imp2);
// Only Pomeron (high energies)
G4double GetPomTotProbability(const G4double s_value, const G4double imp2)
{return 2*(1.-std::exp(-PomEikonal(s_value,imp2)))/pom_C;}
G4double GetPomCohProbability(const G4double s_value, const G4double imp2)
{return sqr(1.-std::exp(-PomEikonal(s_value,imp2)))/pom_C;}
G4double GetPomDiffProbability(const G4double s_value, const G4double imp2)
{return ((pom_C-1.)/pom_C)*GetPomCohProbability(s_value,imp2);}
G4double GetPomDubDiffProbability(const G4double s_value, const G4double imp2)
{return (sqr(pom_sqC-1.)/pom_C)*GetPomCohProbability(s_value,imp2);}
G4double GetPomSinDiffProbability(const G4double s_value, const G4double imp2) //For each T & B
{return ((pom_sqC-1.)/pom_C)*GetPomCohProbability(s_value,imp2);}
G4double GetPomAbsProbability(const G4double s_value, const G4double imp2)
{return (1.-std::exp(-2*PomEikonal(s_value,imp2)))/pom_C;}
G4double GetPomElProbability(const G4double s_value, const G4double imp2)
{return GetPomCohProbability(s_value,imp2)/pom_C;}
G4double GetPomInelProbability(const G4double s_value, const G4double imp2)
{return GetPomDiffProbability(s_value,imp2) + GetPomAbsProbability(s_value,imp2);}
G4double GetCutPomProbability(const G4double s, const G4double ip2, const G4int nPom);
G4double GetCutQexProbability(const G4double s, const G4double ip2, const G4int nQex);
private:
void InitForNucleon();
void InitForHyperon();
void InitForAntiBaryon();
void InitForPion();
void InitForKaon();
void InitForGamma();
G4double Expand(G4double z);
G4double PowerQex(const G4double s_value) {return qex_Gamma/(s_value/S0);} // qex_Alpha=0 (anti-p?)
G4double PowerPom(const G4double s_value) {return pom_Gamma*std::pow(s_value/S0, pom_Alpha-1.);}
G4double SigQex(const G4double s_value) {return 8*CLHEP::pi*CLHEP::hbarc_squared*PowerQex(s_value);}
G4double SigPom(const G4double s_value) {return 8*CLHEP::pi*CLHEP::hbarc_squared*PowerPom(s_value);}
G4double LambdaQex(const G4double s_value) {return qex_R2+qex_Alphaprime*std::log(s_value/S0);}
G4double LambdaPom(const G4double s_value) {return pom_R2+pom_Alphaprime*std::log(s_value/S0);}
G4double ZQex(const G4double s_value) {return 2*PowerQex(s_value)/LambdaQex(s_value);} // qex_C=1.
G4double ZPom(const G4double s_value) {return 2*pom_C*PowerPom(s_value)/LambdaPom(s_value);}
G4double QexEikonal(const G4double s_value, const G4double imp2)
{return ZQex(s_value)*std::exp(-imp2/LambdaQex(s_value)/CLHEP::hbarc_squared/4)/2;}
G4double PomEikonal(G4double s_value, G4double imp2)
{return ZPom(s_value)*std::exp(-imp2/LambdaPom(s_value)/CLHEP::hbarc_squared/4)/2;}
// Body
G4double S0;
G4double pom_Gamma;
G4double pom_C;
G4double pom_sqC;
G4double pom_R2;
G4double pom_Alpha;
G4double pom_Alphaprime;
G4double qex_Gamma;
G4double qex_R2;
G4double qex_Alphaprime;
};
#endif