Rivet analyses

title: DM2_1988_I262690

Cross section for $e^+e^-\to K^+K^-$ between 1.35 and 2.4 GeV

Experiment: DM2 (DCI)

Inspire ID: 262690

Status: VALIDATED

Authors: - Peter Richardson

References: - Z.Phys. C39 (1988) 13

Beams: e+ e-

Beam energies: ANY

Run details: - e+ e- to hadrons

Measurement of the cross section for $e^+e^-\to K^+K^-$ at energies between 1.35 and 2.4 GeV

Source code:DM2_1988_I262690.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief e+e- -> K+K- class DM2_1988_I262690 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(DM2_1988_I262690);


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

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

  // Initialise and register projections
  declare(FinalState(), "FS");

  // Book histograms
  book(_nkaon, "TMP/kaon", refData(1, 1, 1));
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const FinalState& fs = apply<FinalState>(event, "FS");
  if (fs.particles().size() != 2) vetoEvent;
  for (const Particle& p : fs.particles()) {
    if (abs(p.pid()) != PID::KPLUS) vetoEvent;
  }
  _nkaon->fill(sqrtS() / MeV);
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_nkaon, crossSection() / sumOfWeights() / nanobarn);
  Estimate1DPtr mult;
  book(mult, 1, 1, 1);
  barchart(_nkaon, mult);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _nkaon;
/// @}

};

RIVET_DECLARE_PLUGIN(DM2_1988_I262690);

} ```