Rivet analyses

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief D0 and D+ at 29 GeV
  class HRS_1984_I202899 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1984_I202899);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(UnstableParticles(Cuts::abspid == 411 or Cuts::abspid == 421), "UFS");
      //Histograms
      for (unsigned int ix = 0; ix < 2; ++ix) {
        book(_h_sigma[ix], 1, 1, 1 + ix);
        for (unsigned int iy = 0; iy < 2; ++iy) {
          if (ix == 1 && iy == 1) continue;
          book(_h_spect[ix][iy], 3 + iy, 1, 1 + ix);
        }
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p : ufs.particles()) {
        const double xE = 2. * p.E() / sqrtS();
        const double beta = p.p3().mod() / p.E();
        unsigned int iloc = p.abspid() == 421 ? 0 : 1;
        if (xE > 0.5) _h_sigma[iloc]->fill(29);
        _h_spect[iloc][0]->fill(xE, 1. / beta);
        if (iloc == 0) _h_spect[0][1]->fill(xE);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 2; ++ix) {
        scale(_h_sigma[ix], crossSection() / nanobarn / sumOfWeights());
        scale(_h_spect[ix][0], sqr(sqrtS()) * crossSection() / microbarn / sumOfWeights());
      }
      normalize(_h_spect[0][1]);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<int> _h_sigma[2];
    Histo1DPtr _h_spect[2][2];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(HRS_1984_I202899);

}