1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/UnstableParticles.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @brief Add a short analysis description here
 10  class BESIII_2024_I2776394 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2024_I2776394);
 15
 16
 17    /// @name Analysis methods
 18    /// @{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22      // Initialise and register projections
 23      declare(FinalState(), "FS");
 24      declare(UnstableParticles(), "UFS");
 25      book(_h, 1, 1, 1);
 26      for (const string& en : _h.binning().edges<0>()) {
 27        const double end = std::stod(en)*GeV;
 28        if (isCompatibleWithSqrtS(end)) {
 29          _ecms = en;
 30          break;
 31        }
 32      }
 33    }
 34
 35    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
 36      for( const Particle &child : p.children()) {
 37	if(child.children().empty()) {
 38	  --nRes[child.pid()];
 39	  --ncount;
 40	}
 41	else
 42	  findChildren(child,nRes,ncount);
 43      }
 44    }
 45
 46    /// Perform the per-event analysis
 47    void analyze(const Event& event) {
 48      const FinalState& fs = apply<FinalState>(event, "FS");
 49
 50      map<long,int> nCount;
 51      int ntotal(0);
 52      for (const Particle& p : fs.particles()) {
 53      	nCount[p.pid()] += 1;
 54      	++ntotal;
 55      }
 56      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
 57      for (const Particle& p : ufs.particles(Cuts::pid==223)) {
 58	if(p.children().empty()) continue;
 59	map<long,int> nRes = nCount;
 60	int ncount = ntotal;
 61	findChildren(p,nRes,ncount);
 62        // check for eta
 63        for (const Particle& p2 : ufs.particles(Cuts::pid==331)) {
 64          map<long,int> nResB = nRes;
 65          int ncountB = ncount;
 66          findChildren(p2,nResB,ncountB);
 67          if(ncountB!=0) continue;
 68          bool matched = true;
 69          for(auto const & val : nResB) {
 70            if(val.second!=0) {
 71              matched = false;
 72              break;
 73            }
 74          }
 75          if(matched) {
 76            _h->fill(_ecms);
 77            break;
 78          }
 79        }
 80      }
 81    }
 82
 83
 84    /// Normalise histograms etc., after the run
 85    void finalize() {
 86      scale(_h,crossSection()/picobarn/sumOfWeights());
 87    }
 88
 89    /// @}
 90
 91
 92    /// @name Histograms
 93    /// @{
 94    BinnedHistoPtr<string> _h;
 95    string _ecms;
 96    /// @}
 97
 98
 99  };
100
101
102  RIVET_DECLARE_PLUGIN(BESIII_2024_I2776394);
103
104}