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- -> 2pi+ 2pi- pi0 and rho0 omega
 10  class ARGUS_1987_I247567 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1987_I247567);
 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(Cuts::pid==113 || Cuts::pid==223), "UFS");
 25      // histos
 26      for (unsigned int ix=0; ix<2; ++ix) {
 27        book(_c[ix], 1+ix, 1, 1);
 28        for (const string& en : _c[ix].binning().edges<0>()) {
 29          const size_t idx = en.find("-");
 30          if(idx!=std::string::npos) {
 31            const double emin = std::stod(en.substr(0,idx));
 32            const double emax = std::stod(en.substr(idx+1,string::npos));
 33            if(inRange(sqrtS()/GeV, emin, emax)) {
 34              _ecms[ix] = en;
 35              break;
 36            }
 37          }
 38          else {
 39            const double end = std::stod(en)*GeV;
 40            if (isCompatibleWithSqrtS(end)) {
 41              _ecms[ix] = en;
 42              break;
 43            }
 44          }
 45        }
 46      }
 47      if(_ecms[0].empty() && _ecms[1].empty())
 48        MSG_ERROR("Beam energy incompatible with analysis.");
 49    }
 50
 51    void findChildren(const Particle& p,map<long,int>& nRes, int & ncount) {
 52      for (const Particle &child : p.children()) {
 53        if (child.children().empty()) {
 54          nRes[child.pid()]-=1;
 55          --ncount;
 56        }
 57        else {
 58          findChildren(child,nRes,ncount);
 59        }
 60      }
 61    }
 62
 63
 64    /// Perform the per-event analysis
 65    void analyze(const Event& event) {
 66      const FinalState& fs = apply<FinalState>(event, "FS");
 67      // find the final-state particles
 68      map<long,int> nCount;
 69      int ntotal(0);
 70      for (const Particle& p : fs.particles()) {
 71        nCount[p.pid()] += 1;
 72        ++ntotal;
 73      }
 74      if (ntotal==5 && nCount[211]==2 && nCount[-211]==2 && nCount[111]==1) _c[0]->fill(_ecms[0]);
 75      // rho0 mesons
 76      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
 77      for (const Particle& rho : ufs.particles(Cuts::pid==113)) {
 78        if (rho.children().empty()) continue;
 79        map<long,int> nRes=nCount;
 80        int ncount = ntotal;
 81        findChildren(rho,nRes,ncount);
 82        bool matched=false;
 83        // omega
 84        for (const Particle& omega : ufs.particles(Cuts::pid==223)) {
 85       	  if(omega.children().empty()) continue;
 86          map<long,int> nRes2=nRes;
 87          int ncount2 = ncount;
 88          findChildren(omega,nRes2,ncount2);
 89          if(ncount2 !=0 ) continue;
 90          matched = true;
 91      	  for (const auto& val : nRes2) {
 92      	    if (val.second!=0) {
 93      	      matched = false;
 94      	      break;
 95      	    }
 96      	  }
 97          if (matched) {
 98            _c[1]->fill(_ecms[1]);
 99            break;
100          }
101        }
102        if (matched) break;
103      }
104    }
105
106
107    /// Normalise histograms etc., after the run
108    void finalize() {
109      scale(_c, crossSection()/nanobarn/sumOfWeights());
110    }
111
112    /// @}
113
114
115    /// @name Histograms
116    /// @{
117    BinnedHistoPtr<string> _c[2];
118    string _ecms[2];
119    /// @}
120
121
122  };
123
124
125  RIVET_DECLARE_PLUGIN(ARGUS_1987_I247567);
126
127}