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ARGUS_1992_I319102

Measurement of $R$ at 9.36 GeV and charged particle multiplicities in continuum and at the $\Upsilon(4S)$
Experiment: ARGUS (DORIS)
Inspire ID: 319102
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C54 (1992) 13-20, 1992
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization) Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Measurement of $R$ at 9.36 GeV and charged particle multiplicities in continuum and at the $\Upsilon(4S)$. 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. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: ARGUS_1992_I319102.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/UnstableParticles.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @brief charged multiplicity at 4s and nearby continuum
 10  class ARGUS_1992_I319102 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1992_I319102);
 15
 16
 17    /// @name Analysis methods
 18    //@{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22
 23      // Initialise and register projections
 24      declare(UnstableParticles(), "UFS");
 25      declare(FinalState(), "FS");
 26
 27      // Book histograms
 28      if(isCompatibleWithSqrtS(10.47)) {
 29        book(_h_N, 2, 1, 1);
 30        book(_h_tot_N,4,1,1);
 31      }
 32      book(_h_N_Upsilon, 3, 1, 1);
 33      book(_h_N_tot_Upsilon,5,1,1);
 34      // counters for R
 35      book(_c_hadrons, "/TMP/sigma_hadrons");
 36      book(_c_muons, "/TMP/sigma_muons");
 37      book(_w_cont,"/TMP/w_cont");
 38      book(_w_ups ,"/TMP/w_ups" );
 39    }
 40
 41    /// Recursively walk the decay tree to find decay products of @a p
 42    void findDecayProducts(Particle mother, unsigned int & nCharged) {
 43      for(const Particle & p: mother.children()) {
 44	if(!p.children().empty())
 45	  findDecayProducts(p, nCharged);
 46	else if(PID::isCharged(p.pid()))
 47	  ++nCharged;
 48      }
 49    }
 50
 51
 52    /// Perform the per-event analysis
 53    void analyze(const Event& event) {
 54      const FinalState& fs = apply<FinalState>(event, "FS");
 55      // Find the Upsilons among the unstables
 56      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
 57      Particles upsilons = ufs.particles(Cuts::pid==300553);
 58      // Continuum
 59      if (upsilons.empty()) {
 60	map<long,int> nCount;
 61	int ntotal(0);
 62	unsigned int nCharged(0);
 63	for (const Particle& p : fs.particles()) {
 64	  nCount[p.pid()] += 1;
 65	  ++ntotal;
 66	  if(PID::isCharged(p.pid())) ++nCharged;
 67	}
 68	// mu+mu- + photons
 69	if(nCount[-13]==1 and nCount[13]==1 &&
 70	   ntotal==2+nCount[22])
 71	  _c_muons->fill();
 72	// everything else
 73	else {
 74	  _c_hadrons->fill();
 75	  if(_h_N) {
 76	    _h_N->fill(nCharged);
 77	    _h_tot_N->fill(10.47,nCharged);
 78	    _w_cont->fill();
 79	  }
 80	}
 81      }
 82      // upsilon 4s
 83      else {
 84        for (const Particle& ups : upsilons) {
 85	  unsigned int nCharged(0);
 86	  findDecayProducts(ups,nCharged);
 87	  _h_N_Upsilon->fill(nCharged);
 88	  _h_N_tot_Upsilon->fill(10.575,nCharged);
 89	  _w_ups->fill();
 90	}
 91      }
 92    }
 93
 94
 95    /// Normalise histograms etc., after the run
 96    void finalize() {
 97      Scatter1D R = *_c_hadrons/ *_c_muons;
 98      double              rval = R.point(0).x();
 99      pair<double,double> rerr = R.point(0).xErrs();
100      double fact = crossSection()/ sumOfWeights() /picobarn;
101      double sig_h = _c_hadrons->val()*fact;
102      double err_h = _c_hadrons->err()*fact;
103      double sig_m = _c_muons  ->val()*fact;
104      double err_m = _c_muons  ->err()*fact;
105      Scatter2D temphisto(refData(1, 1, 1));
106      Scatter2DPtr hadrons;
107      book(hadrons, "sigma_hadrons");
108      Scatter2DPtr muons;
109      book(muons, "sigma_muons"  );
110      Scatter2DPtr mult;
111      book(mult, 1, 1, 1);
112      for (size_t b = 0; b < temphisto.numPoints(); b++) {
113	const double x  = temphisto.point(b).x();
114	pair<double,double> ex = temphisto.point(b).xErrs();
115	pair<double,double> ex2 = ex;
116	if(ex2.first ==0.) ex2. first=0.0001;
117	if(ex2.second==0.) ex2.second=0.0001;
118	if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
119	  mult   ->addPoint(x, rval, ex, rerr);
120	  hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
121	  muons  ->addPoint(x, sig_m, ex, make_pair(err_m,err_m));
122	}
123	else {
124	  mult   ->addPoint(x, 0., ex, make_pair(0.,.0));
125	  hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
126	  muons  ->addPoint(x, 0., ex, make_pair(0.,.0));
127	}
128      }
129      if(_h_N) {
130	normalize(_h_N,200.);
131	if(_w_cont->val()!=0)
132	  scale(_h_tot_N,1./ *_w_cont);
133      }
134      normalize(_h_N_Upsilon,200.);
135      if(_w_ups->val()!=0)
136	scale(_h_N_tot_Upsilon,1./ *_w_ups);
137    }
138
139    //@}
140
141
142    /// @name Histograms
143    //@{
144    Histo1DPtr _h_N,_h_N_Upsilon,_h_tot_N,_h_N_tot_Upsilon;
145    CounterPtr _c_hadrons, _c_muons;
146    CounterPtr _w_cont,_w_ups;
147    //@}
148
149
150  };
151
152
153  // The hook for the plugin system
154  RIVET_DECLARE_PLUGIN(ARGUS_1992_I319102);
155
156
157}