MG_qqx2ttx.h

// -*- C++ -*-
//
// MG_qqx2ttx.h is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2019 The Herwig Collaboration
//
// Herwig is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef MG5_Sigma_sm_qqx2ttx_H
#define MG5_Sigma_sm_qqx2ttx_H
//
// This is the declaration of the MG_qqx2ttx class.
//
 
#include <complex> 
#include <vector> 
#include "Parameters_sm.h"
 
using namespace std; 
 
 
class MG_qqx2ttx
{
  public:
 
    // Constructor.
    MG_qqx2ttx() {}
 
    // Initialize process using Herwig parameters
    virtual void initProc(map<string, double> & MGParams); 
 
    // Calculate flavour-independent parts of cross section.
    virtual void sigmaKin(vector<std::complex<double> >& amps, const vector<int>& hel); 
 
    // Set momenta for matrix element evaluation
    void setMomenta(vector < double * > & momenta){p = momenta;}
 
    // number of external particles
    static const int nexternal = 4; 
 
    // number of colour ordered amplitudes 
    static const int namplitudes = 1; 
    std::complex<double> amp[namplitudes]; 
 
  private:
    // Calculate wavefunctions
    void calculate_wavefunctions(const int perm[], const int hel[]); 
 
    // number of wavefunctions used in calculate_wavefunctions 
    static const int nwavefuncs = 5; 
    std::complex<double> w[nwavefuncs][18]; 
 
    // Pointer to the model parameters
    Parameters_sm * pars; 
 
    // vector with external particle masses
    vector<double> mME; 
 
    // vector with momenta 
    vector < double * > p; 
 
}; 
 
 
#endif  // MG5_Sigma_sm_qqx2ttx_H