Rivet analyses

title: DM1_1979_I141565

Cross section for $e^+e^-\to p\bar{p}$ between 1.925 and 2.18 GeV

Experiment: DM1 (DCI)

Inspire ID: 141565

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B86 (1979) 395-398, 1979

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Measurement of the cross section for $e^+e^-\to p\bar{p}$ between 1.925 and 2.18 GeV.

Source code:DM1_1979_I141565.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief e+e- > p pbar class DM1_1979_I141565 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(DM1_1979_I141565);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  declare(FinalState(), "FS");
  book(_nProton, "/TMP/nProton", refData(1, 1, 1));
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const FinalState& fs = apply<FinalState>(event, "FS");
  // total hadronic and muonic cross sections
  map<long, int> nCount;
  int ntotal(0);
  for (const Particle& p : fs.particles()) {
    nCount[p.pid()] += 1;
    ++ntotal;
  }
  if (ntotal == 2 && nCount[2212] == 1 && nCount[-2212] == 1) _nProton->fill(sqrtS() / GeV);
}


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

/// @}


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

};

RIVET_DECLARE_PLUGIN(DM1_1979_I141565);

} ```