Rivet analyses

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

namespace Rivet {


  /// @brief Xi- and Sigma*+/- spectra
  class HRS_1987_I246162 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1987_I246162);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projects
      declare(UnstableParticles(Cuts::abspid == 3114 || Cuts::abspid == 3224 || Cuts::abspid == 3312
                                || Cuts::abspid == 3122),
              "UFS");
      const ChargedFinalState cfs;
      declare(cfs, "CFS");
      // histos
      for (unsigned int ix = 0; ix < 2; ++ix) {
        for (unsigned int iy = 0; iy < 2; ++iy) book(_h_total[ix][iy], 1 + ix, 1, 1 + iy);
        book(_h_x[ix], 4, 1, 1 + ix);
        book(_h_ratio[ix], 3, 1, 1 + ix);
      }
      book(_c, "TMP/nLam");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const ChargedFinalState& cfs = apply<ChargedFinalState>(event, "CFS");
      const size_t numParticles = cfs.particles().size();

      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
      if (numParticles < 2) {
        MSG_DEBUG("Failed leptonic event cut");
        vetoEvent;
      }
      MSG_DEBUG("Passed leptonic event cut");
      for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles()) {
        if (p.abspid() == 3122) {
          _c->fill();
          continue;
        }
        double xE = 2. * p.E() / sqrtS();
        Vector3 mom3 = p.p3();
        const double energy = p.E();
        double modp = mom3.mod();
        double beta = modp / energy;
        unsigned int iloc = p.abspid() == 3312 ? 1 : 0;
        _h_ratio[iloc]->fill(29);
        if (iloc == 0 && xE > 0.1 && xE < 0.8)
          _h_total[iloc][0]->fill(29);
        else if (iloc == 1 && xE > 0.05 && xE < 0.75)
          _h_total[iloc][0]->fill(29);
        _h_total[iloc][1]->fill(29);
        _h_x[iloc]->fill(xE, 1. / beta);
      }
    }


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

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<int> _h_total[2][2], _h_ratio[2];
    Histo1DPtr _h_x[2];
    CounterPtr _c;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(HRS_1987_I246162);

}