Rivet analyses

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

namespace Rivet {


  /// @brief e+ e- > Upsilon(2,3S) gamma at 10.52 and 10.58
  class CLEO_1999_I474676 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_1999_I474676);


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

    /// Book histograms and initialise projections before the run
    void init() {
      declare(FinalState(), "FS");
      declare(UnstableParticles(Cuts::pid==100553 || Cuts::pid==200553), "UFS");
      book(_nUps2pipi, 1,1,2);
      book(_nUps3pipi, 1,1,1);
      for (const string& en : _nUps2pipi.binning().edges<0>()) {
        const double eval = stod(en);
        if (isCompatibleWithSqrtS(eval)) {
          _sqs = en; break;
        }
      }
      raiseBeamErrorIf(_sqs.empty());
    }

    void findChildren(const Particle& p, map<long,int>& nRes, int& ncount) const {
      for (const Particle &child : p.children()) {
        if (child.children().empty()) {
          --nRes[child.pid()];
          --ncount;
        }
        else {
          findChildren(child,nRes,ncount);
        }
      }
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");
      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        nCount[p.pid()] += 1;
        ++ntotal;
      }
      const FinalState& ufs = apply<FinalState>(event, "UFS");
      for (const Particle& p : ufs.particles()) {
        if (p.children().empty()) continue;
        map<long,int> nRes = nCount;
        int ncount = ntotal;
        findChildren(p,nRes,ncount);
        if (ncount!=1) continue;
        bool matched = true;
        for (const auto& val : nRes) {
          if (val.first==22) {
            if (val.second!=1) {
              matched = false;
              break;
            }
          }
          else if (val.second!=0) {
            matched = false;
            break;
          }
        }
        if (matched) {
          if (p.pid()==100553)       _nUps2pipi->fill(_sqs);
          else if (p.pid()==200553)  _nUps3pipi->fill(_sqs);
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      const double fact = crossSection()/ sumOfWeights() /picobarn;
      scale(_nUps3pipi, fact);
      scale(_nUps2pipi, fact);
    }
    /// @}

    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _nUps2pipi,_nUps3pipi;
    string _sqs = "";
    /// @}

  };


  RIVET_DECLARE_PLUGIN(CLEO_1999_I474676);


}