Rivet analyses

title: BELLE_2012_I1090664

Cross sections for $\gamma\gamma\to\omega\phi$, $\phi\phi$ and $\omega\omega$

Experiment: BELLE (KEKB)

Inspire ID: 1090664

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 108 (2012) 232001

Beams: 22 22

Beam energies: ANY

Run details: - gamma gamma to hadrons

Measurement of the cross sections for $\gamma\gamma\to\omega\phi$, $\phi\phi$ and $\omega\omega$.

Source code:BELLE_2012_I1090664.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief gamma gamma -> omega phi, omega omega and phi phi class BELLE_2012_I1090664 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2012_I1090664);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  declare(FinalState(), "FS");
  declare(UnstableParticles(Cuts::pid == 223 || Cuts::pid == 333), "UFS");
  // counters
  for (unsigned int ix = 0; ix < 3; ++ix) {
    for (unsigned int iy = 0; iy < 2; ++iy) {
      book(_sigma[ix][iy], "TMP/c_" + toString(ix + 1) + "_" + toString(iy + 1),
           refData(1, ix + 1, 1 + iy));
    }
  }
}

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");
  // find the final-state particles
  map<long, int> nCount;
  int ntotal(0);
  for (const Particle& p : fs.particles()) {
    nCount[p.pid()] += 1;
    ++ntotal;
  }
  // find any rho mesons
  Particles mesons = apply<UnstableParticles>(event, "UFS").particles();
  for (unsigned int ix = 0; ix < mesons.size(); ++ix) {
    if (mesons[ix].children().empty()) continue;
    map<long, int> nRes = nCount;
    int ncount = ntotal;
    findChildren(mesons[ix], nRes, ncount);
    bool matched = false;
    for (unsigned int iy = ix + 1; iy < mesons.size(); ++iy) {
      if (mesons[iy].children().empty()) continue;
      map<long, int> nRes2 = nRes;
      int ncount2 = ncount;
      findChildren(mesons[iy], nRes2, ncount2);
      if (ncount2 != 0) continue;
      matched = true;
      for (const auto& val : nRes2) {
        if (val.second != 0) {
          matched = false;
          break;
        }
      }
      if (matched) {
        if (mesons[ix].pid() != mesons[iy].pid()) {
          for (unsigned int iy = 0; iy < 2; ++iy) {
            _sigma[0][iy]->fill(sqrtS());
          }
        }
        else if (mesons[ix].pid() == 333) {
          for (unsigned int iy = 0; iy < 2; ++iy) {
            _sigma[1][iy]->fill(sqrtS());
          }
        }
        else if (mesons[ix].pid() == 223) {
          for (unsigned int iy = 0; iy < 2; ++iy) {
            _sigma[2][iy]->fill(sqrtS());
          }
        }
        break;
      }
    }
    if (matched) break;
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  const double fact = crossSection() / nanobarn / sumOfWeights();
  // loop over tables in paper
  for (unsigned int ix = 0; ix < 3; ++ix) {
    for (unsigned int iy = 0; iy < 2; ++iy) {
      scale(_sigma[ix][iy], fact);
      Estimate1DPtr tmp;
      book(tmp, 1, ix + 1, 1 + iy);
      barchart(_sigma[ix][iy], tmp);
    }
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _sigma[3][2];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2012_I1090664);

} ```