Rivet analyses

title: PLUTO_1982_I166799

Measurement of $R$ between 3.6 and 30 GeV and hadronic cross section from 9.3 to 9.48 GeV

Experiment: PLUTO (PETRA)

Inspire ID: 166799

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rept. 83 (1982) 151-280, 1982

Beams: e- e+

Beam energies: (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.4, 2.4); (2.5, 2.5); (3.9, 3.9); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (4.7, 4.7); (6.0, 6.0); (6.5, 6.5); (8.5, 8.5); (11.0, 11.0); (13.8, 13.8)GeV

Run details: - e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ in $e^+e^-$ collisions for energies between 3.6 and 30 GeV. The hadronic cross section is also measured in the $\Upsilon$ region, 9.3 to 9.48 GeV. The individual hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalculated if runs are combined.

Source code:PLUTO_1982_I166799.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief R measurement class PLUTO_1982_I166799 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(PLUTO_1982_I166799);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  declare(FinalState(), "FS");
  // counters for R
  book(_c_hadrons[0], "/TMP/sigma_hadrons", refData<YODA::BinnedEstimate<string>>(1, 1, 1));
  book(_c_hadrons[1], 2, 1, 1);
  book(_c_muons, "/TMP/sigma_muons", refData<YODA::BinnedEstimate<string>>(1, 1, 1));
  for (size_t ix = 0; ix < 2; ++ix) {
    for (const string& en : _c_hadrons[ix].binning().edges<0>()) {
      const size_t idx = en.find("-");
      if (idx != string::npos) {
        const double emin = stod(en.substr(0, idx));
        const double emax = stod(en.substr(idx + 1, string::npos));
        if (inRange(sqrtS() / GeV, emin, emax)) {
          _sqs[ix] = en;
          break;
        }
      }
      else {
        const double eval = stod(en) * GeV;
        if (isCompatibleWithSqrtS(eval)) {
          _sqs[ix] = en;
          break;
        }
      }
    }
  }
  raiseBeamErrorIf(_sqs[0].empty() && _sqs[1].empty());
}


/// 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 && nCount[13] == 1 && ntotal == 2 + nCount[22]) {
    // mu+mu- + photons
    _c_muons->fill(_sqs[0]);
  }
  else {
    // everything else
    _c_hadrons[0]->fill(_sqs[0]);
    _c_hadrons[1]->fill(_sqs[1]);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_c_hadrons[1], crossSection() / sumOfWeights() / nanobarn);
  BinnedEstimatePtr<string> mult;
  book(mult, 1, 1, 1);
  divide(_c_hadrons[0], _c_muons, mult);
}

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<string> _c_hadrons[2], _c_muons;
string _sqs[2];
/// @}

};

RIVET_DECLARE_PLUGIN(PLUTO_1982_I166799); } ```