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 Cross section for $e^+e^-\to \omega\chi_{c(1,2)}$ at energies between 4.42 and 4.6 GeV
 10  class BESIII_2015_I1406939 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2015_I1406939);
 15
 16
 17    /// @name Analysis methods
 18    /// @{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22      declare(FinalState(), "FS");
 23      declare(UnstableParticles(), "UFS");
 24      book(_nChi1, "TMP/chi1");
 25      book(_nChi2, "TMP/chi2");
 26    }
 27
 28    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
 29      for( const Particle &child : p.children()) {
 30        if(child.children().empty()) {
 31          --nRes[child.pid()];
 32          --ncount;
 33        }
 34        else
 35          findChildren(child,nRes,ncount);
 36      }
 37    }
 38
 39    /// Perform the per-event analysis
 40    void analyze(const Event& event) {
 41      const FinalState& fs = apply<FinalState>(event, "FS");
 42      map<long,int> nCount;
 43      int ntotal(0);
 44      for (const Particle& p :  fs.particles()) {
 45        nCount[p.pid()] += 1;
 46        ++ntotal;
 47      }
 48      const FinalState& ufs = apply<FinalState>(event, "UFS");
 49      bool matched = false;
 50      for (const Particle& p :  ufs.particles(Cuts::pid==20443 or Cuts::pid==445)) {
 51        if(p.children().empty()) continue;
 52        map<long,int> nRes = nCount;
 53        int ncount = ntotal;
 54        findChildren(p,nRes,ncount);
 55        for (const Particle& p2 :  ufs.particles(Cuts::pid==223)) {
 56          map<long,int> nRes2 = nRes;
 57          int ncount2 = ncount;
 58          findChildren(p2,nRes2,ncount2);
 59          if(ncount2!=0) continue;
 60          matched=true;
 61          for(auto const & val : nRes2) {
 62            if(val.second!=0) {
 63              matched = false;
 64              break;
 65            }
 66          }
 67          if(matched) {
 68            if(p.pid()==20443)
 69              _nChi1->fill();
 70            else if(p.pid()==445)
 71              _nChi2->fill();
 72            break;
 73          }
 74        }
 75        if(matched) break;
 76      }
 77    }
 78
 79
 80    /// Normalise histograms etc., after the run
 81    void finalize() {
 82
 83      double fact =  crossSection()/ sumOfWeights() /picobarn;
 84      for(unsigned int ix=2;ix<4;++ix) {
 85        double sigma(0.),error(0.);
 86        if(ix==2) {
 87          sigma = _nChi1->val()*fact;
 88          error = _nChi1->err()*fact;
 89        }
 90        else if(ix==3) {
 91          sigma = _nChi2->val()*fact;
 92          error = _nChi2->err()*fact;
 93        }
 94        Estimate1DPtr  mult;
 95        book(mult, ix, 1, 6);
 96        for (auto& b : mult->bins()) {
 97          if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
 98            b.set(sigma, error);
 99          }
100        }
101      }
102
103    }
104
105    /// @}
106
107
108    /// @name Histograms
109    /// @{
110    CounterPtr _nChi1,_nChi2;
111    /// @}
112
113
114  };
115
116
117  RIVET_DECLARE_PLUGIN(BESIII_2015_I1406939);
118
119
120}