SigmaOnia.h

// SigmaOnia.h is a part of the PYTHIA event generator.
// Copyright (C) 2024 Torbjorn Sjostrand.
// PYTHIA is licenced under the GNU GPL v2 or later, see COPYING for details.
// Please respect the MCnet Guidelines, see GUIDELINES for details.

// Header file for charmonia/bottomonia process differential cross sections.
// Contains classes derived from SigmaProcess via Sigma2Process.

#ifndef Pythia8_SigmaOnia_H
#define Pythia8_SigmaOnia_H

#include "Pythia8/SigmaProcess.h"

namespace Pythia8 {

//==========================================================================

// A helper class used to check onia settings. Used for the parton shower
// and hard process.

class OniaSetup {

protected:

  // Constructors.
  OniaSetup() = default;
  OniaSetup(Info* infoPtrIn, int flavourIn, string pre = "");

  // Intialise and check settings.
  void initStates(string wave, const vector<int> &states,
    vector<int> &jnums, bool &valid, bool duplicate = true);
  void initSettings(string wave, unsigned int size,
    const vector<string> &names, vector< vector<double> > &pvecs, bool &valid);
  void initSettings(string wave, unsigned int size,
    const vector<string> &names, vector< vector<bool> > &fvecs, bool &valid);

  // Stored pointers.
  Info* infoPtr = {};
  Logger* loggerPtr = {};
  Settings* settingsPtr = {};
  ParticleData* particleDataPtr = {};

  // Stored vectors of settings.
  vector<int> states3S1, states3PJ, spins3S1, spins3PJ;
  vector<string> meNames3S1, meNames3PJ;
  vector< vector<double> > mes3S1, mes3PJ;

  // Stored validity and production flags.
  bool onia{}, onia3S1{}, onia3PJ{}, oniaFlavour{},
    valid3S1{true}, valid3PJ{true};
  int flavour{};
  string cat, key;

  // Stored parameters.
  double mSplit{};

};

//==========================================================================

// A helper class used to setup the onia processes.

class SigmaOniaSetup : public OniaSetup {

public:

  // Constructors.
  SigmaOniaSetup() = default;
  SigmaOniaSetup(Info* infoPtrIn, int flavourIn);

  // Initialise the SigmaProcesses for gg, qg, qqbar.
  void setupSigma2gg(vector<SigmaProcessPtr> &procs, bool oniaIn = false);
  void setupSigma2qg(vector<SigmaProcessPtr> &procs, bool oniaIn = false);
  void setupSigma2qq(vector<SigmaProcessPtr> &procs, bool oniaIn = false);

private:

  // Additional stored validity and production flags.
  bool onia3DJ{true}, valid3DJ{true}, validDbl3S1{true};

  // Stored vectors of settings.
  vector<int> states3DJ, spins3DJ, states1Dbl3S1, states2Dbl3S1, spins1Dbl3S1,
    spins2Dbl3S1;
  vector<string> meNames3DJ, meNamesDbl3S1;
  vector< vector<double> > mes3DJ, mesDbl3S1;
  vector<string> ggNames3S1, qgNames3S1, qqNames3S1,
    ggNames3PJ, qgNames3PJ, qqNames3PJ, ggNames3DJ, qgNames3DJ, qqNames3DJ,
    dblNames3S1;
  vector< vector<bool> > ggs3S1, qgs3S1, qqs3S1, ggs3PJ, qgs3PJ, qqs3PJ,
    ggs3DJ, qgs3DJ, qqs3DJ, dbls3S1;

};

//==========================================================================

// A derived class for g g -> QQbar[3S1(1)] g (Q = c or b).

class Sigma2gg2QQbar3S11g : public Sigma2Process {

public:

  // Constructor.
  Sigma2gg2QQbar3S11g(int idHadIn, double oniumMEIn, int codeIn) :
    idHad(abs(idHadIn)), codeSave(codeIn), oniumME(oniumMEIn), sigma() {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "gg";}
  virtual int    id3Mass() const {return idHad;}

 private:

  // Values stored for process type and colour flow selection.
  int    idHad, codeSave;
  string nameSave;
  double oniumME, sigma;

};

//==========================================================================

// A derived class for g g -> QQbar[3S1(1)] gamma (Q = c or b).

class Sigma2gg2QQbar3S11gm : public Sigma2Process {

public:

  // Constructor.
  Sigma2gg2QQbar3S11gm(int idHadIn, double oniumMEIn, int codeIn) :
    idHad(abs(idHadIn)), codeSave(codeIn), qEM2(), oniumME(oniumMEIn),
    sigma() {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "gg";}
  virtual int    id3Mass() const {return idHad;}

 private:

  // Values stored for process type and colour flow selection.
  int    idHad, codeSave;
  string nameSave;
  double qEM2, oniumME, sigma;

};

//==========================================================================

// A derived class for g g -> QQbar[3PJ(1)] g (Q = c or b, J = 0, 1 or 2).

class Sigma2gg2QQbar3PJ1g : public Sigma2Process {

public:

  // Constructor.
  Sigma2gg2QQbar3PJ1g(int idHadIn, double oniumMEIn, int jIn, int codeIn) :
    idHad(idHadIn), jSave(jIn), codeSave(codeIn), oniumME(oniumMEIn), sigma()
    {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "gg";}
  virtual int    id3Mass() const {return idHad;}

protected:

  // Name pre-, post-, and mid-fix.
  virtual string namePrefix()  const {return "g g";}
  virtual string namePostfix() const {return "g";}
  string nameMidfix() const {return (codeSave - codeSave%100)/100
      == 4 ? "ccbar" : "bbbar";}

  // Values stored for process type and colour flow selection.
  int    idHad, jSave, codeSave;
  string nameSave;
  double oniumME, sigma;

};

//==========================================================================

// A derived class for q g -> QQbar[3PJ(1)] q (Q = c or b, J = 0, 1 or 2).

class Sigma2qg2QQbar3PJ1q : public Sigma2gg2QQbar3PJ1g {

public:

  // Constructor.
  Sigma2qg2QQbar3PJ1q(int idHadIn, double oniumMEIn, int jIn, int codeIn) :
    Sigma2gg2QQbar3PJ1g(idHadIn, oniumMEIn, jIn, codeIn) {}

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string inFlux()  const {return "qg";}

protected:

  // Name pre- and post-fix.
  string namePrefix()  const {return "q g";}
  string namePostfix() const {return "q";}

};

//==========================================================================

// A derived class for q qbar -> QQbar[3PJ(1)] g (Q = c or b, J = 0, 1 or 2).

class Sigma2qqbar2QQbar3PJ1g : public Sigma2gg2QQbar3PJ1g {

public:

  // Constructor.
  Sigma2qqbar2QQbar3PJ1g(int idHadIn, double oniumMEIn, int jIn, int codeIn) :
    Sigma2gg2QQbar3PJ1g(idHadIn, oniumMEIn, jIn, codeIn) {}

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string inFlux()  const {return "qqbarSame";}

protected:

  // Name pre- and post-fix.
  string namePrefix()  const {return "q qbar";}
  string namePostfix() const {return "g";}

};

//==========================================================================

// A derived class for g g -> QQbar[3DJ(1)] g (Q = c or b).

class Sigma2gg2QQbar3DJ1g : public Sigma2gg2QQbar3PJ1g {

public:

  // Constructor.
  Sigma2gg2QQbar3DJ1g(int idHadIn, double oniumMEIn, int jIn, int codeIn) :
    Sigma2gg2QQbar3PJ1g(idHadIn, oniumMEIn, jIn, codeIn) {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

};

//==========================================================================

// A derived class for g g -> QQbar[X(8)] g (Q = c or b, X = 3S1, 1S0 or 3PJ).

class Sigma2gg2QQbarX8g : public Sigma2Process {

public:

  // Constructor.
  Sigma2gg2QQbarX8g(int idHadIn, double oniumMEIn, int stateIn,
    double mSplitIn, int codeIn) : idHad(idHadIn), stateSave(stateIn),
    codeSave(codeIn), oniumME(oniumMEIn), sigma(), mSplit(mSplitIn) {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "gg";}
  virtual int    id3Mass() const {return idHad;}

protected:

  // Name pre- and post-fix.
  virtual string namePrefix()  const {return "g g";}
  virtual string namePostfix() const {return "g";}

  // Values stored for process type and colour flow selection.
  int    idHad, stateSave, codeSave;
  string nameSave;
  double oniumME, sigma, mSplit;

};

//==========================================================================

// A derived class for q g -> QQbar[X(8)] q (Q = c or b, X = 3S1, 1S0 or 3PJ).

class Sigma2qg2QQbarX8q : public Sigma2gg2QQbarX8g {

public:

  // Constructor.
  Sigma2qg2QQbarX8q(int idHadIn, double oniumMEIn, int stateIn,
    double mSplitIn, int codeIn) :
    Sigma2gg2QQbarX8g(idHadIn, oniumMEIn, stateIn, mSplitIn, codeIn) {}

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string inFlux()  const {return "qg";}

protected:

  // Name pre- and post-fix.
  virtual string namePrefix()  const {return "q g";}
  virtual string namePostfix() const {return "q";}

};

//==========================================================================

// A derived class for q qbar -> QQbar[X(8)] g (Q = c or b,
// X = 3S1, 1S0 or 3PJ).

class Sigma2qqbar2QQbarX8g : public Sigma2gg2QQbarX8g {

public:

  // Constructor.
  Sigma2qqbar2QQbarX8g(int idHadIn, double oniumMEIn, int stateIn,
    double mSplitIn, int codeIn) :
    Sigma2gg2QQbarX8g(idHadIn, oniumMEIn, stateIn, mSplitIn, codeIn) {}

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string inFlux()  const {return "qqbarSame";}

protected:

  // Name pre- and post-fix.
  virtual string namePrefix()  const {return "q qbar";}
  virtual string namePostfix() const {return "g";}

};

//==========================================================================

// A derived class for g g -> QQbar[3S1(1)] QQbar[3S1(1)] (Q = c or b).

class Sigma2gg2QQbar3S11QQbar3S11 : public Sigma2Process {

public:

  // Constructor.
  Sigma2gg2QQbar3S11QQbar3S11(int idHad1In, int idHad2In,
    double oniumME1In, double oniumME2In, int codeIn) :
    idHad1(abs(idHad1In)), idHad2(abs(idHad2In)), codeSave(codeIn),
    oniumME1(oniumME1In), oniumME2(oniumME2In), sigma() {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "gg";}
  virtual int    id3Mass() const {return idHad1;}
  virtual int    id4Mass() const {return idHad2;}

 private:

  // Values stored for process type and colour flow selection.
  int    idHad1, idHad2, codeSave;
  string nameSave;
  double oniumME1, oniumME2, sigma;
  vector<double> m2V;

};

//==========================================================================

// A derived class for q qbar -> QQbar[3S1(1)] QQbar[3S1(1)] (Q = c or b).

class Sigma2qqbar2QQbar3S11QQbar3S11 : public Sigma2Process {

public:

  // Constructor.
  Sigma2qqbar2QQbar3S11QQbar3S11(int idHad1In, int idHad2In,
    double oniumME1In, double oniumME2In, int codeIn) :
    idHad1(abs(idHad1In)), idHad2(abs(idHad2In)), codeSave(codeIn), m2(),
    oniumME1(oniumME1In), oniumME2(oniumME2In), sigma() {}

  // Initialize process.
  virtual void initProc();

  // Calculate flavour-independent parts of cross section.
  virtual void sigmaKin();

  // Evaluate d(sigmaHat)/d(tHat).
  virtual double sigmaHat() {return sigma;}

  // Select flavour, colour and anticolour.
  virtual void setIdColAcol();

  // Info on the subprocess.
  virtual string name()    const {return nameSave;}
  virtual int    code()    const {return codeSave;}
  virtual string inFlux()  const {return "qqbarSame";}
  virtual int    id3Mass() const {return idHad1;}
  virtual int    id4Mass() const {return idHad2;}

 private:

  // Values stored for process type and colour flow selection.
  int    idHad1, idHad2, codeSave;
  string nameSave;
  double m2, oniumME1, oniumME2, sigma;

};

//==========================================================================

} // end namespace Pythia8

#endif // Pythia8_SigmaOnia_H