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 CMD2_2005_I658856 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_2005_I658856);
 15
 16
 17    /// @name Analysis methods
 18    /// @{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22
 23      // Initialise and register projections
 24      declare(FinalState(), "FS");
 25      declare(UnstableParticles(), "UFS");
 26      book(_numEtaGamma, "TMP/EtaGamma");
 27      book(_numPi0Gamma, "TMP/Pi0Gamma");
 28    }
 29
 30    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
 31      for (const Particle &child : p.children()) {
 32	if(child.children().empty()) {
 33	  --nRes[child.pid()];
 34	  --ncount;
 35	}
 36	else
 37	  findChildren(child,nRes,ncount);
 38      }
 39    }
 40
 41    /// Perform the per-event analysis
 42    void analyze(const Event& event) {
 43
 44      const FinalState& fs = apply<FinalState>(event, "FS");
 45
 46      map<long,int> nCount;
 47      int ntotal(0);
 48      for (const Particle& p : fs.particles()) {
 49	nCount[p.pid()] += 1;
 50	++ntotal;
 51      }
 52      if(ntotal==2 && nCount[22]==1 && nCount[111]==1)
 53	_numPi0Gamma->fill();
 54
 55
 56      const FinalState& ufs = apply<FinalState>(event, "UFS");
 57      for (const Particle& p : ufs.particles()) {
 58	if(p.children().empty()) continue;
 59	// find the omega
 60	if(p.pid()==221) {
 61	  map<long,int> nRes = nCount;
 62	  int ncount = ntotal;
 63	  findChildren(p,nRes,ncount);
 64	  // eta pi+pi-
 65	  if(ncount!=1) continue;
 66	  bool matched = true;
 67	  for(auto const & val : nRes) {
 68	    if(val.first==22) {
 69	      if(val.second !=1) {
 70		matched = false;
 71		break;
 72	      }
 73	    }
 74	    else if(val.second!=0) {
 75	      matched = false;
 76	      break;
 77	    }
 78	  }
 79	  if(matched)
 80	    _numEtaGamma->fill();
 81	}
 82      }
 83
 84    }
 85
 86
 87    /// Normalise histograms etc., after the run
 88    void finalize() {
 89
 90      for (unsigned int ix=1;ix<3;++ix) {
 91        double sigma,error;
 92        if(ix==1) {
 93          sigma = _numEtaGamma->val();
 94          error = _numEtaGamma->err();
 95        }
 96        else {
 97          sigma = _numPi0Gamma->val();
 98          error = _numPi0Gamma->err();
 99        }
100        sigma *= crossSection()/ sumOfWeights() /nanobarn;
101        error *= crossSection()/ sumOfWeights() /nanobarn;
102        Estimate1DPtr mult;
103        book(mult, ix, 1, 1);
104        for (auto& b : mult->bins()) {
105          if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
106            b.set(sigma, error);
107          }
108        }
109      }
110    }
111
112    /// @}
113
114
115    /// @name Histograms
116    /// @{
117    CounterPtr _numEtaGamma,_numPi0Gamma;
118    /// @}
119
120
121  };
122
123
124  RIVET_DECLARE_PLUGIN(CMD2_2005_I658856);
125
126
127}