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Rivet analyses reference

MARKI_1977_I119979

Measurement of $R$ for energies between 3.598 and 3.886 GeV
Experiment: MARKI (Spear)
Inspire ID: 119979
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev.Lett. 39 (1977) 526, 1977
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$ and the hadronic cross section for energies between 3.598 and 3.886 GeV. The hadronic and muonic cross sections are also outputted to the yoda file so that ratio $R$ can be recalcuated if runs are combined.

Source code: MARKI_1977_I119979.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4
  5namespace Rivet {
  6
  7
  8  /// @brief Add a short analysis description here
  9  class MARKI_1977_I119979 : public Analysis {
 10  public:
 11
 12    /// Constructor
 13    RIVET_DEFAULT_ANALYSIS_CTOR(MARKI_1977_I119979);
 14
 15
 16    /// @name Analysis methods
 17    //@{
 18
 19    /// Book histograms and initialise projections before the run
 20    void init() {
 21      declare(FinalState(), "FS");
 22      // Book histograms
 23      book(_c_hadrons, "/TMP/sigma_hadrons");
 24      book(_c_muons, "/TMP/sigma_muons");
 25    }
 26
 27
 28    /// Perform the per-event analysis
 29    void analyze(const Event& event) {
 30      const FinalState& fs = apply<FinalState>(event, "FS");
 31
 32      map<long,int> nCount;
 33      int ntotal(0);
 34      for (const Particle& p : fs.particles()) {
 35	nCount[p.pid()] += 1;
 36	++ntotal;
 37      }
 38      // mu+mu- + photons
 39      if(nCount[-13]==1 and nCount[13]==1 &&
 40	 ntotal==2+nCount[22])
 41	_c_muons->fill();
 42      // everything else
 43      else
 44	_c_hadrons->fill();
 45    }
 46
 47
 48    /// Normalise histograms etc., after the run
 49    void finalize() {
 50      // R
 51      Scatter1D R = *_c_hadrons/ *_c_muons;
 52      double              rval = R.point(0).x();
 53      pair<double,double> rerr = R.point(0).xErrs();
 54      double fact = crossSection()/ sumOfWeights() /nanobarn;
 55      double sig_h = _c_hadrons->val()*fact;
 56      double err_h = _c_hadrons->err()*fact;
 57      double sig_m = _c_muons  ->val()*fact;
 58      double err_m = _c_muons  ->err()*fact;
 59      Scatter2D temphisto(refData(1, 1, 1));
 60      Scatter2DPtr hadrons;
 61      book(hadrons, "simga_hadrons");
 62      Scatter2DPtr muons;
 63      book(muons, "sigma_muons"  );
 64      Scatter2DPtr mult1;
 65      book(mult1, 1,1,1);
 66      Scatter2DPtr mult2;
 67      book(mult2, 2,1,1);
 68      for (size_t b = 0; b < temphisto.numPoints(); b++) {
 69	const double x  = temphisto.point(b).x();
 70	pair<double,double> ex = temphisto.point(b).xErrs();
 71	pair<double,double> ex2 = ex;
 72	if(ex2.first ==0.) ex2. first=0.0001;
 73	if(ex2.second==0.) ex2.second=0.0001;
 74	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
 75	  mult1   ->addPoint(x, rval, ex, rerr);
 76	  mult2   ->addPoint(x, rval, ex, rerr);
 77	  hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
 78	  muons  ->addPoint(x, sig_m, ex, make_pair(err_m,err_m));
 79	}
 80	else {
 81	  mult1   ->addPoint(x, 0., ex, make_pair(0.,.0));
 82	  mult2   ->addPoint(x, 0., ex, make_pair(0.,.0));
 83	  hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
 84	  muons  ->addPoint(x, 0., ex, make_pair(0.,.0));
 85	}
 86      }
 87    }
 88
 89    //@}
 90
 91
 92    /// @name Histograms
 93    //@{
 94    CounterPtr _c_hadrons, _c_muons;
 95    //@}
 96
 97
 98  };
 99
100
101  // The hook for the plugin system
102  RIVET_DECLARE_PLUGIN(MARKI_1977_I119979);
103
104
105}