Rivet analyses

title: CLEOC_2008_I777917

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++

// -- 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);

} ```