Rivet analyses

title: MARKII_1985_I207785

$K^0$ and $K^+$ production at 29 GeV

Experiment: MARKII (PEP)

Inspire ID: 207785

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 59 (1987) 2412, 1987.

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: - e+ e- to hadrons at 29 GeV

Rate and spectrum for $K^0$ and $K^+$ production at 29 GeV measured by the MARKII collaboration.

Source code:MARKII_1985_I207785.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief K+/K0 specta at 29 GeV class MARKII_1985_I207785 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MARKII_1985_I207785);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  declare(UnstableParticles(), "UFS");
  //Histograms
  book(_h["K0"], 2, 1, 1);
  book(_h["Kp"], 4, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p :
       ufs.particles(Cuts::abspid == 321 or Cuts::abspid == 310 or Cuts::abspid == 130)) {
    const double xp = p.p3().mod();
    const double beta = p.p3().mod() / p.E();
    if (p.abspid() == 321)
      _h["Kp"]->fill(xp, 1. / beta);
    else
      _h["K0"]->fill(xp, 1. / beta);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // cross section differential in xp, now plotting p so need to convert
  scale(_h, 1. / sumOfWeights() * sqrtS() / 2);
}

///@}


/// @name Histograms
///@{
map<string, Histo1DPtr> _h;
///@}

};

RIVET_DECLARE_PLUGIN(MARKII_1985_I207785);

} ```