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 e+e- -> omega pi+ pi-
 10  class BESIII_2023_I2643786 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2023_I2643786);
 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      for (unsigned int ix=0; ix<7; ++ix) {
 26        book(_n[ix], "TMP/n_"+toString(ix+1));
 27      }
 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
 42    /// Perform the per-event analysis
 43    void analyze(const Event& event) {
 44      const FinalState& fs = apply<FinalState>(event, "FS");
 45      map<long,int> nCount;
 46      int ntotal(0);
 47      for (const Particle& p : fs.particles()) {
 48      	nCount[p.pid()] += 1;
 49      	++ntotal;
 50      }
 51      const FinalState& ufs = apply<FinalState>(event, "UFS");
 52      bool hasOmegaPiPi=false, hasResonance=false;
 53      for (const Particle& p : ufs.particles(Cuts::pid==223)) {
 54      	if (p.children().empty()) continue;
 55      	map<long,int> nRes = nCount;
 56      	int ncount = ntotal;
 57       	findChildren(p,nRes,ncount);
 58        // first the omega pi pi final state
 59        if (ncount==2) {
 60          hasOmegaPiPi=true;
 61          for (const auto& val : nRes) {
 62            if (abs(val.first)==211) {
 63              if (val.second !=1) {
 64                hasOmegaPiPi = false;
 65                break;
 66              }
 67            }
 68            else if(val.second!=0) {
 69              hasOmegaPiPi = false;
 70              break;
 71            }
 72          }
 73          if (hasOmegaPiPi) _n[0]->fill();
 74        }
 75        if (!hasOmegaPiPi) continue;
 76       	// now omega + second resonance
 77       	for (const Particle& p2 : ufs.particles(Cuts::pid==9000221 ||
 78                                                Cuts::pid==9010221 ||
 79                                                Cuts::pid==10221 ||
 80                                                Cuts::pid==225)) {
 81          if (p2.children().empty()) continue;
 82          map<long,int> nRes2 = nRes;
 83          int ncount2 = ncount;
 84          findChildren(p2,nRes2,ncount2);
 85          hasResonance=true;
 86          if (ncount2!=0) continue;
 87          for (const auto& val : nRes2) {
 88            if (val.second!=0) {
 89              hasResonance = false;
 90              break;
 91            }
 92          }
 93          if (hasResonance) {
 94            if      (p2.pid()==9000221 ) _n[1]->fill();
 95            else if (p2.pid()==9010221 ) _n[2]->fill();
 96            else if (p2.pid()==10221   ) _n[3]->fill();
 97            else if (p2.pid()==225     ) _n[4]->fill();
 98            break;
 99          }
100        }
101      	if (hasOmegaPiPi) break;
102      }
103      if (hasResonance || !hasOmegaPiPi) return;
104      // b_1 pi
105      for (const Particle& p : ufs.particles(Cuts::abspid==10213 || Cuts::abspid==100213)) {
106      	if (p.children().empty()) continue;
107        map<long,int> nRes = nCount;
108        int ncount = ntotal;
109        findChildren(p,nRes,ncount);
110        if (ncount!=1) continue;
111        int ipi = -p.pid()/p.abspid()*211;
112        hasResonance=true;
113        for (const auto& val : nRes) {
114          if (val.first==ipi) {
115            if (val.second !=1) {
116              hasOmegaPiPi = false;
117              break;
118            }
119          }
120          else if (val.second!=0) {
121            hasResonance = false;
122            break;
123          }
124        }
125        if (hasResonance) {
126          if (p.abspid()==10213) _n[5]->fill();
127          else                   _n[6]->fill();
128          break;
129        }
130      }
131    }
132
133
134    /// Normalise histograms etc., after the run
135    void finalize() {
136      for (unsigned int ix=0; ix<7; ++ix) {
137        scale(_n[ix], crossSection()/ sumOfWeights() /picobarn);
138        unsigned int ih=2, iy=ix;
139        if (ix==0) {
140          ih=1;
141          iy=1;
142        }
143        Estimate1DPtr mult;
144        book(mult, ih, 1, iy);
145        for (auto& b : mult->bins()) {
146          if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
147            b.set(_n[ix]->val(), _n[ix]->err());
148          }
149        }
150      }
151    }
152
153    /// @}
154
155
156    /// @name Histograms
157    /// @{
158    CounterPtr _n[7];
159    /// @}
160
161
162  };
163
164
165  RIVET_DECLARE_PLUGIN(BESIII_2023_I2643786);
166
167}