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PLUTO_1979_I140818

Hadronic cross section in $e^+e^-$ collisions for energies between 9.4 to 9.48
Experiment: PLUTO (PETRA)
Inspire ID: 140818
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C1 (1979) 343, 1979
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of the hadronic cross section in $e^+e^-$ collisions for energies between 9.4 to 9.48 GeV.

Source code: PLUTO_1979_I140818.cc
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// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"

namespace Rivet {


  /// @brief Add a short analysis description here
  class PLUTO_1979_I140818 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(PLUTO_1979_I140818);


    /// @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, "/TMP/sigma_hadrons");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");

      map<long,int> nCount;
      int ntotal(0);
      unsigned int nCharged(0);
      for (const Particle& p : fs.particles()) {
	nCount[p.pid()] += 1;
	++ntotal;
	if(PID::isCharged(p.pid())) ++nCharged;
      }
      // mu+mu- + photons
      if(nCount[-13]==1 and nCount[13]==1 &&
	 ntotal==2+nCount[22])
	vetoEvent;
      // everything else
      else {
	_c_hadrons->fill();
      }

    }


    /// Normalise histograms etc., after the run
    void finalize() {
      double fact = crossSection()/ sumOfWeights() /nanobarn;
      double sig_h = _c_hadrons->val()*fact;
      double err_h = _c_hadrons->err()*fact;
      Scatter2D temphisto(refData(2, 1, 1));
      Scatter2DPtr hadrons;
      book(hadrons, 2, 1, 1);
      for (size_t b = 0; b < temphisto.numPoints(); b++) {
	const double x  = temphisto.point(b).x();
	pair<double,double> ex = temphisto.point(b).xErrs();
	pair<double,double> ex2 = ex;
	if(ex2.first ==0.) ex2. first=0.0001;
	if(ex2.second==0.) ex2.second=0.0001;
	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
	  hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
	}
	else {
	  hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
	}
      }
    }

    //@}


    /// @name Histograms
    //@{
    CounterPtr _c_hadrons;
    //@}


  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(PLUTO_1979_I140818);


}