Rivet analyses

Measurement of charm final-states, the total hadronic cross section and R for energies between 3.92 and 4.26 GeV

Experiment: CLEOC (CESR)

Inspire ID: 777917

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D80 (2009) 072001, 2009

Beams: e- e+

Beam energies: ANY

Run details: - e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of charm final-states, the total hadronic cross section and R for energies between 3.92 and 4.26 GeV The muonic cross section is also outputted to the yoda file so that ratio R can be recalcuated if runs are combined.

Source code:CLEOC_2008_I777917.cc

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

namespace Rivet {


  /// @brief Charm cross sections 3.92 and 4.26 GeV
  class CLEOC_2008_I777917 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOC_2008_I777917);


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

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

      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      for (unsigned int ix = 0; ix < 3; ++ix)
        for (unsigned int iy = 0; iy < 3; ++iy) book(_sigma_DD[ix][iy], 1 + ix, 1, 1 + iy);
      for (unsigned int ix = 0; ix < 2; ++ix) {
        book(_sigma_DDpi[ix], 4, 1, 1 + ix);
        book(_sigma_DDX[ix], 5, 1, 1 + ix);
      }
      book(_sigma_R[0], "TMP/hadron", refData<YODA::BinnedEstimate<int>>(6, 1, 1));
      book(_sigma_R[1], "TMP/muon", refData<YODA::BinnedEstimate<int>>(6, 1, 1));
      book(_sigma_cc, 6, 1, 1);
    }

    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");
      // total hadronic and muonic cross sections
      map<long, int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        nCount[p.pid()] += 1;
        ++ntotal;
      }
      // mu+mu- + photons
      if (nCount[-13] == 1 and nCount[13] == 1 && ntotal == 2 + nCount[22]) {
        _sigma_R[1]->fill(round(sqrtS() / MeV));
        return;
      }
      else
        _sigma_R[0]->fill(round(sqrtS() / MeV));
      // identified final state with D mesons
      const FinalState& ufs = apply<UnstableParticles>(event, "UFS");
      for (unsigned int ix = 0; ix < ufs.particles().size(); ++ix) {
        const Particle& p1 = ufs.particles()[ix];
        int id1 = abs(p1.pid());
        if (id1 != 411 && id1 != 413 && id1 != 421 && id1 != 423 && id1 != 431 && id1 != 433) continue;
        // check fs
        bool fs = true;
        for (const Particle& child : p1.children()) {
          if (child.pid() == p1.pid()) {
            fs = false;
            break;
          }
        }
        if (!fs) continue;
        // find the children
        map<long, int> nRes = nCount;
        int ncount = ntotal;
        findChildren(p1, nRes, ncount);
        bool matched = false;
        int sign = p1.pid() / id1;
        // loop over the other fs particles
        for (unsigned int iy = ix + 1; iy < ufs.particles().size(); ++iy) {
          const Particle& p2 = ufs.particles()[iy];
          fs = true;
          for (const Particle& child : p2.children()) {
            if (child.pid() == p2.pid()) {
              fs = false;
              break;
            }
          }
          if (!fs) continue;
          if (p2.pid() / abs(p2.pid()) == sign) continue;
          int id2 = abs(p2.pid());
          if (id2 != 411 && id2 != 413 && id2 != 421 && id2 != 423 && id2 != 431 && id2 != 433) continue;
          if (!p2.parents().empty() && p2.parents()[0].pid() == p1.pid()) continue;
          if ((id1 == 411 || id1 == 421 || id1 == 431) && (id2 == 411 || id2 == 421 || id2 == 431)) {
            _sigma_DDX[1]->fill(round(sqrtS() / MeV));
            _sigma_cc->fill(round(sqrtS() / MeV));
          }
          map<long, int> nRes2 = nRes;
          int ncount2 = ncount;
          findChildren(p2, nRes2, ncount2);
          if (ncount2 == 0) {
            matched = true;
            for (const auto& val : nRes2) {
              if (val.second != 0) {
                matched = false;
                break;
              }
            }
            if (matched) {
              if (id1 == 411 && id2 == 411) {
                _sigma_DD[1][0]->fill(round(sqrtS() / MeV));
                _sigma_DDX[0]->fill(round(sqrtS() / MeV));
              }
              else if (id1 == 421 && id2 == 421) {
                _sigma_DD[0][0]->fill(round(sqrtS() / MeV));
                _sigma_DDX[0]->fill(round(sqrtS() / MeV));
              }
              else if (id1 == 431 && id2 == 431) {
                _sigma_DD[2][0]->fill(round(sqrtS() / MeV));
              }
              else if (id1 == 413 && id2 == 413) {
                _sigma_DD[1][2]->fill(round(sqrtS() / MeV));
              }
              else if (id1 == 423 && id2 == 423) {
                _sigma_DD[0][2]->fill(round(sqrtS() / MeV));
              }
              else if (id1 == 433 && id2 == 433) {
                _sigma_DD[2][2]->fill(round(sqrtS() / MeV));
              }
              else if ((id1 == 421 && id2 == 423) || (id1 == 423 && id2 == 421)) {
                _sigma_DD[0][1]->fill(round(sqrtS() / MeV));
              }
              else if ((id1 == 411 && id2 == 413) || (id1 == 413 && id2 == 411)) {
                _sigma_DD[1][1]->fill(round(sqrtS() / MeV));
              }
              else if ((id1 == 431 && id2 == 433) || (id1 == 433 && id2 == 431)) {
                _sigma_DD[2][1]->fill(round(sqrtS() / MeV));
              }
            }
          }
          else if (ncount2 == 1) {
            int ipi = 0;
            if (nRes2[111] == 1 && nRes2[211] == 0 && nRes[-211] == 0)
              ipi = 111;
            else if (nRes2[111] == 0 && nRes2[211] == 1 && nRes[-211] == 0)
              ipi = 211;
            else if (nRes2[111] == 0 && nRes2[211] == 0 && nRes[-211] == 1)
              ipi = -211;
            if (ipi == 0) continue;
            matched = true;
            for (const auto& val : nRes2) {
              if (val.first == ipi)
                continue;
              else if (val.second != 0) {
                matched = false;
                break;
              }
            }
            if (matched) {
              bool Ddecay = false;
              Particle mother = p1;
              while (!mother.parents().empty()) {
                mother = mother.parents()[0];
                if (PID::isCharmMeson(mother.pid()) && mother.pid() != p1.pid()) {
                  Ddecay = true;
                  break;
                }
              }
              mother = p2;
              while (!mother.parents().empty()) {
                mother = mother.parents()[0];
                if (PID::isCharmMeson(mother.pid()) && mother.pid() != p1.pid()) {
                  Ddecay = true;
                  break;
                }
              }
              if (Ddecay) continue;
              if ((id1 == 413 || id1 == 423) && (id2 == 413 || id2 == 423)) {
                _sigma_DDpi[1]->fill(round(sqrtS() / MeV));
              }
              else if ((id1 == 411 || id1 == 421) && (id2 == 413 || id2 == 423)) {
                _sigma_DDpi[0]->fill(round(sqrtS() / MeV));
              }
              else if ((id1 == 413 || id1 == 423) && (id2 == 411 || id2 == 421)) {
                _sigma_DDpi[0]->fill(round(sqrtS() / MeV));
              }
            }
          }
        }
      }
    }

    /// Normalise histograms etc., after the run
    void finalize() {
      // cross sections
      double fact = crossSection() / picobarn / sumOfWeights();
      for (unsigned int ix = 0; ix < 3; ++ix)
        for (unsigned int iy = 0; iy < 3; ++iy) scale(_sigma_DD[ix][iy], fact);
      for (unsigned int ix = 0; ix < 2; ++ix) {
        scale(_sigma_DDpi[ix], fact);
        scale(_sigma_DDX[ix], fact * 1e-3); // this one in nb
      }
      BinnedEstimatePtr<int> tmp;
      book(tmp, 6, 1, 2);
      divide(_sigma_R[0], _sigma_R[1], tmp);
      scale(_sigma_cc, fact * 1e-3);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<int> _sigma_DD[3][3];
    BinnedHistoPtr<int> _sigma_DDpi[2];
    BinnedHistoPtr<int> _sigma_DDX[2];
    BinnedHistoPtr<int> _sigma_R[2], _sigma_cc;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(CLEOC_2008_I777917);


}