Rivet analyses

Cross section for e⁺e⁻ → D^+D^− and D^±D^*∓ between 4.08 and 4.6 GeV

Experiment: BESIII (BEPC)

Inspire ID: 1989527

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - JHEP 05 (2022) 155

Beams: e+ e-

Beam energies: (2.0, 2.0); (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); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3)GeV

Run details: - e+e- to hadrons

Cross section for e⁺e⁻ → D^*+D^*− and D^±D^*∓ between 4.08 and 4.6 GeV.

Source code:`BESIII_2022_I1989527.cc`

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

namespace Rivet {


  /// @brief e+e- > D*+D*-, D+- D*-+
  class BESIII_2022_I1989527 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I1989527);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      book(_nDSS, 1, 1, 3);
      book(_nDS, 2, 1, 3);
      for (const string& en : _nDS.binning().edges<0>()) {
        const double eval = stod(en) * GeV;
        if (isCompatibleWithSqrtS(eval)) {
          _sqs = en;
          break;
        }
      }
      raiseBeamErrorIf(_sqs.empty());
    }

    void findChildren(const Particle& p, map<long, int>& nRes, int& ncount) const {
      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;
      }
      const FinalState& ufs = apply<FinalState>(event, "UFS");

      for (size_t ix = 0; ix < ufs.particles().size(); ++ix) {
        const Particle& p1 = ufs.particles()[ix];
        if (p1.abspid() != 413) continue;
        map<long, int> nRes = nCount;
        int ncount = ntotal;
        findChildren(p1, nRes, ncount);
        bool matched = false;
        int sign = -p1.pid() / abs(p1.pid());
        for (unsigned int iy = 0; iy < ufs.particles().size(); ++iy) {
          if (ix == iy) continue;
          const Particle& p2 = ufs.particles()[iy];
          if (!p2.parents().empty() && p2.parents()[0].pid() == p1.pid()) {
            continue;
          }
          if (p2.pid() != sign * 413 && p2.pid() != sign * 411) continue;
          map<long, int> nRes2 = nRes;
          int ncount2 = ncount;
          findChildren(p2, nRes2, ncount2);
          if (ncount2 != 0) continue;
          matched = true;
          for (const auto& val : nRes2) {
            if (val.second != 0) {
              matched = false;
              break;
            }
          }
          if (matched) {
            sign = abs(p2.pid());
            break;
          }
        }
        if (matched) {
          if (sign == 411)
            _nDS->fill(_sqs);
          else if (sign == 413)
            _nDSS->fill(_sqs);
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale({_nDS, _nDSS}, crossSection() / sumOfWeights() / picobarn);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _nDSS, _nDS;
    string _sqs = "";
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BESIII_2022_I1989527);

}

Rivet analyses

Cross section for e+e− → D*+D*− and D±D*∓ between 4.08 and 4.6 GeV

Source code:BESIII_2022_I1989527.cc

Cross section for e⁺e⁻ → D^+D^− and D^±D^*∓ between 4.08 and 4.6 GeV

Source code:`BESIII_2022_I1989527.cc`