Rivet analyses

title: TOPAZ_1995_I381777

Cross section in $e^+e^-\to$hadrons for 57.77 GeV

Experiment: TOPAZ (Tristan)

Inspire ID: 381777

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B347 (1995) 171-178, 1995

Beams: e- e+

Beam energies: (28.9, 28.9)GeV

Run details: - e+ e- to hadrons

Measurement of the hadronic cross section in $e^+e^-$ collisions by TOPAZ for 57.77 GeV.

Source code:TOPAZ_1995_I381777.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief Add a short analysis description here class TOPAZ_1995_I381777 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(TOPAZ_1995_I381777);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  declare(FinalState(), "FS");

  // Book histograms
  book(_c_hadrons, 1, 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 (nCount[-13] == 1 and nCount[13] == 1 && ntotal == 2 + nCount[22]) {
    vetoEvent; // mu+mu- + photons
  }
  else {
    _c_hadrons->fill(Ecm); // everything else
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  const double fact = crossSection() / sumOfWeights() / picobarn;
  scale(_c_hadrons, fact);
}

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<string> _c_hadrons;
const string Ecm = "57.77";
/// @}

};

RIVET_DECLARE_PLUGIN(TOPAZ_1995_I381777);

} ```