Rivet analyses

title: MARKI_1975_I100592

Cross section and charged particle multiplicity for energies between 2.6 and 5 GeV

Experiment: MARKI (SPEAR)

Inspire ID: 100592

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 34 (1975) 764, 1975

Beams: e- e+

Beam energies: (1.2, 1.2); (1.3, 1.3); (1.4, 1.4); (1.5, 1.5); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.7, 1.7); (1.8, 1.8); (1.9, 1.9); (2.0, 2.0); (2.0, 2.0); (2.1, 2.1); (2.1, 2.1); (2.2, 2.2); (2.3, 2.3); (2.4, 2.4); (2.5, 2.5)GeV

Run details: - e+e- to hadrons

Cross section and harged particle multiplicity for energies between 2.6 and 5 GeV.

Source code:MARKI_1975_I100592.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {

/// @brief cross section and charged multiplicity class MARKI_1975_I100592 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MARKI_1975_I100592);


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

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

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

  // Book histograms
  book(_nEvent, 1, 1, 1);
  book(_nHadrons, 2, 1, 1);
  for (const string& en : _nEvent.binning().edges<0>()) {
    double eval = stod(en) * GeV;
    if (isCompatibleWithSqrtS(eval)) {
      _sqs = en;
      break;
    }
  }
  raiseBeamErrorIf(_sqs.empty());
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const ChargedFinalState& fs = apply<ChargedFinalState>(event, "FS");
  _nEvent->fill(_sqs);
  _nHadrons->fill(_sqs, fs.particles().size());
}

/// Normalise histograms etc., after the run
void finalize() {
  scale(_nEvent, crossSection() / sumOfWeights() / nanobarn);
}

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<string> _nEvent;
BinnedProfilePtr<string> _nHadrons;
string _sqs = "";
/// @}

};

RIVET_DECLARE_PLUGIN(MARKI_1975_I100592);

} ```