Rivet analyses

Cross section for e+e− → KS0KL0 with π0, η and π0π0 between threshold and 4 GeV

Experiment: BABAR (PEP-II)

Inspire ID: 1511276

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev. D95 (2017) no.5, 052001

Beams: e+ e-

Beam energies: (0.6, 0.6); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0)GeV

Run details: - e+e- to hadrons

Cross section for e+e− → KS0KL0 with π0, η and π0π0 between threshold and 4 GeV using radiative events.

Source code:BABAR_2017_I1511276.cc

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief e+e- -> K_S0K_L0 with pi0, eta and 2pi0
  class BABAR_2017_I1511276 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2017_I1511276);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {

      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");

      // Book histograms
      bool pass = false;
      for (size_t ix=0; ix<_sqs.size(); ++ix) {
        book(_sigma[ix], 1+ix, 1, 1);
        for (const string& en : _sigma[ix].binning().edges<0>()) {
          const double eval = std::stod(en);
          if (isCompatibleWithSqrtS(eval)) {
            _sqs[ix] = en;
            pass = true;
            break;
          }
        }
      }
      raiseBeamErrorIf(!pass);
    }

    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
      for (const Particle &child : p.children()) {
        if (child.children().empty()) {
          nRes[child.pid()]-=1;
          --ncount;
        }
        else {
          findChildren(child,nRes,ncount);
        }
      }
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");
      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        nCount[p.pid()] += 1;
        ++ntotal;
      }
      // stable histos
      if (ntotal == 3 && nCount[130] == 1 &&
          nCount[310] == 1 && nCount[111] == 1) {
        if (!_sqs[0].empty()) _sigma[0]->fill(_sqs[0]);
      }
      else if (ntotal == 4 && nCount[130] == 1 &&
                 nCount[310] == 1 && nCount[111] == 2) {
        if(!_sqs[3].empty()) _sigma[3]->fill(_sqs[3]);
      }
      // unstable particles
      const FinalState& ufs = apply<FinalState>(event, "UFS");
      for (const Particle& p : ufs.particles()) {
        if (p.children().empty()) continue;
        if (p.pid()!=333 && p.pid()!=221) continue;
        map<long,int> nRes=nCount;
        int ncount = ntotal;
        findChildren(p,nRes,ncount);
        bool matched  = true;
        if (p.pid()==333 && ncount==1) {
          for (const auto& val : nRes) {
            if (val.first==111) {
              if (val.second!=1) {
                matched = false;
                break;
              }
            }
            else if (val.second!=0) {
              matched = false;
              break;
            }
          }
          if (matched) {
            if(!_sqs[1].empty()) _sigma[1]->fill(_sqs[1]);
          }
        }
        else if (p.pid()==221 && ncount==2) {
          for (const auto& val : nRes) {
            if (val.first==130 || val.first==310) {
              if (val.second!=1) {
                matched = false;
                break;
              }
            }
            else if (val.second!=0) {
              matched = false;
              break;
            }
          }
          if (matched) {
            if (!_sqs[2].empty()) _sigma[2]->fill(_sqs[2]);
          }
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_sigma, crossSection()/ sumOfWeights() /nanobarn);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _sigma[4];
    vector<string> _sqs{""s, ""s, ""s, ""s};
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BABAR_2017_I1511276);


}