Rivet analyses

title: CMD2_1999_I502164

Cross section for $e^+e^-\to K^0_SK^0_L$ at energies near the $\phi$ mass

Experiment: CMD2 (VEPP-2M)

Inspire ID: 502164

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B466 (1999) 385, 1999

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Source code:CMD2_1999_I502164.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief e+ e- > KS0 KL0 class CMD2_1999_I502164 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_1999_I502164);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(FinalState(), "FS");
  for (unsigned int ix = 0; ix < 4; ++ix)
    book(_sigma[ix], "TMP/sigma_" + toString(ix), refData(1 + ix, 1, 1));
}


/// 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;
  }
  if (ntotal == 2 && nCount[130] == 1 && nCount[310] == 1) {
    for (unsigned int ix = 0; ix < 4; ++ix) _sigma[ix]->fill(sqrtS() / MeV);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  double fact = crossSection() / sumOfWeights() / nanobarn;
  for (unsigned int ix = 0; ix < 4; ++ix) {
    scale(_sigma[ix], fact);
    Estimate1DPtr tmp;
    book(tmp, 1 + ix, 1, 1);
    barchart(_sigma[ix], tmp);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _sigma[4];
/// @}

};

RIVET_DECLARE_PLUGIN(CMD2_1999_I502164);

} ```