rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

TASSO_1984_I195333

Measurements of charged particle multiplicities, $R$ and event shapes between 12 and 43 GeV
Experiment: TASSO (PETRA)
Inspire ID: 195333
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C22 (1984) 307-340, 1984
Beams: e- e+
Beam energies: ANY
Run details:
  • e+ e- to hadrons and e+ e- to mu+ mu- (for normalization)

Measurement of $R$, charged particle multiplicites and event shapes in $e^+e^-$ collisions for energies between 12 and 43 GeV. The average charged particle multiplicity, thrust and sphericity are measured for a range of energies. The distributions are available for 12, 22 and 34 GeV. The individual 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: TASSO_1984_I195333.cc
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/Sphericity.hh"
#include "Rivet/Projections/Thrust.hh"

namespace Rivet {


  /// @brief Add a short analysis description here
  class TASSO_1984_I195333 : public Analysis {
  public:

    /// Constructor
    DEFAULT_RIVET_ANALYSIS_CTOR(TASSO_1984_I195333);


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      const FinalState fs;
      declare(fs, "FS");
      declare(Sphericity(fs), "Sphericity");
      declare(Thrust(fs), "Thrust");
      
      // counters for R
      book(_c_hadrons, "/TMP/sigma_hadrons");
      book(_c_muons, "/TMP/sigma_muons");
      book(_h_weight, "/TMP/HWeight");
      unsigned int iloc(0);
      if(fuzzyEquals(sqrtS()/GeV, 14 , 1E-3))
	iloc = 1;
      else if(fuzzyEquals(sqrtS()/GeV, 22 , 1E-3))
	iloc = 2;
      else if(fuzzyEquals(sqrtS()/GeV, 34 , 1E-3))
	iloc = 3;
      if(iloc!=0) {
	book(_h_mult,  3,1,iloc);
	book(_h_p,  5,1,iloc);
	book(_h_xp,  6,1,iloc);
	book(_h_pl,  7,1,iloc);
	book(_h_pt,  8,1,iloc);
	book(_h_pt2,  9,1,iloc);
	book(_h_xl, 10,1,iloc);
	book(_h_xT, 11,1,iloc);
	book(_h_S, 12,1,iloc);
	book(_h_T, 13,1,iloc);
	book(_h_y, 14,1,iloc);
      }
    }


    /// 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]) {	
	_c_muons->fill();
	return;
      }
      // everything else
      _c_hadrons->fill();
      _h_weight->fill();
      _n_charged.fill(nCharged);
      _n_total.fill(ntotal);
      // thrust
      const Thrust& thrust = apply<Thrust>(event, "Thrust");
      _thrust.fill(thrust.thrust());
      // sphericity
      const Sphericity& sphericity = apply<Sphericity>(event, "Sphericity");
      _sphericity.fill(sphericity.sphericity());
      // global distributions
      if(_h_mult) _h_mult->fill(nCharged);
      if(_h_S)    _h_S   ->fill(sphericity.sphericity());
      if(_h_T)    _h_T   ->fill(thrust.thrust());
      // single particle distributions
      for (const Particle& p : fs.particles()) {
	if(!PID::isCharged(p.pid())) continue;
	const Vector3 mom3 = p.p3();
	double pp = mom3.mod();
	_p_total.fill(pp);
	if(_h_p)  _h_p ->fill(pp);
	if(_h_xp) _h_xp->fill(2.*pp/sqrtS());
        const double mom = dot(sphericity.sphericityAxis(), mom3);
	_p_l.fill(fabs(mom));
	if(_h_pl) _h_pl->fill(fabs(mom));
	if(_h_xl) _h_xl->fill(2.*fabs(mom)/sqrtS());
        const double pTin = dot(mom3, sphericity.sphericityMajorAxis());
	_pt2_in.fill(sqr(pTin));
        const double pTout = dot(mom3, sphericity.sphericityMinorAxis());
	_pt2_out.fill(sqr(pTout));
        double pT = sqr(pTin) + sqr(pTout);
	_pt2.fill(pT);
	if(_h_pt2) _h_pt2->fill(pT);
	pT=sqrt(pT);
	_pt.fill(pT);
	if(_h_pt) _h_pt->fill(pT);
	if(_h_xT) _h_xT->fill(2.*pT/sqrtS());
	if(_h_y) {
	  const double rap = 0.5 * log((p.E() + mom) /
				       (p.E() - mom));
	  _h_y->fill(fabs(rap));
	}
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      Scatter1D R = *_c_hadrons/ *_c_muons;
      double              rval = R.point(0).x();
      pair<double,double> rerr = R.point(0).xErrs();
      double fact = crossSection()/ sumOfWeights() /picobarn;
      double sig_h = _c_hadrons->val()*fact;
      double err_h = _c_hadrons->err()*fact;
      double sig_m = _c_muons  ->val()*fact;
      double err_m = _c_muons  ->err()*fact;
      Scatter2D temphisto(refData(1, 1, 1));
      Scatter2DPtr hadrons;
      book(hadrons, "sigma_hadrons");
      Scatter2DPtr muons;
      book(muons, "sigma_muons"  );
      Scatter2DPtr mult;
      book(mult, 1, 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)) {
	  mult   ->addPoint(x, rval, ex, rerr);
	  hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
	  muons  ->addPoint(x, sig_m, ex, make_pair(err_m,err_m));
	}
	else {
	  mult   ->addPoint(x, 0., ex, make_pair(0.,.0));
	  hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
	  muons  ->addPoint(x, 0., ex, make_pair(0.,.0));
	}
      }
      // charged particle multiplicity distribution
      if(_h_mult) normalize(_h_mult,2.);
      for(unsigned int iy=1;iy<12;++iy) {
	double value = 0.0, error = 0.0;
	if(iy==1) {
	  value = _n_charged.xMean();
	  error = _n_charged.xStdErr();
	}
	else if(iy==2) {
	  double num = _n_charged.xMean();
	  double den =   _n_total.xMean();
	  value = num/den;
	  error = value*sqrt(sqr(_n_charged.xStdErr()/num)+sqr(_n_total.xStdErr()/den));
	}
	else if(iy==3) {
	  value = _n_charged.xStdDev();
	  error = _n_charged.xStdErr();
	}
	else if(iy==4) {
	  value = _sphericity.xMean();
	  error = _sphericity.xStdErr();
	}
	else if(iy==5) {
	  value = _thrust.xMean();
	  error = _thrust.xStdErr();
	}
	else if(iy==6) {
	  value = _p_total.xMean();
	  error = _p_total.xStdErr();
	}
	else if(iy==7) {
	  value = _p_l.xMean();
	  error = _p_l.xStdErr();
	}
	else if(iy==8) {
	  value = _pt.xMean();
	  error = _pt.xStdErr();
	}
	else if(iy==9) {
	  value = _pt2.xMean();
	  error = _pt2.xStdErr();
	}
	else if(iy==10) {
	  value = _pt2_in.xMean();
	  error = _pt2_in.xStdErr();
	}
	else if(iy==11) {
	  value = _pt2_out.xMean();
	  error = _pt2_out.xStdErr();
	}
	Scatter2D temphisto(refData(4, 1, iy));
	Scatter2DPtr mult;
	book(mult, 4, 1, iy);
	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)) {
	    mult   ->addPoint(x, value, ex, make_pair(error,error));
	  }
	  else {
	    mult   ->addPoint(x, 0., ex, make_pair(0.,.0));
	  }
	}
      }
      // scale the distributions
      scale(_h_p  ,1./_h_weight->sumW());
      scale(_h_xp ,1./_h_weight->sumW());
      scale(_h_pl ,1./_h_weight->sumW());
      scale(_h_pt ,1./_h_weight->sumW());
      scale(_h_pt2,1./_h_weight->sumW());
      scale(_h_xl ,1./_h_weight->sumW());
      scale(_h_xT ,1./_h_weight->sumW());
      scale(_h_S  ,1./_h_weight->sumW());
      scale(_h_T  ,1./_h_weight->sumW());
      scale(_h_y  ,1./_h_weight->sumW());
    }

    //@}


    /// @name Histograms
    //@{
    Histo1DPtr _h_mult,_h_p,_h_xp,_h_pl,_h_pt,_h_pt2,_h_xl,_h_xT,_h_S,_h_T,_h_y;
    CounterPtr _c_hadrons, _c_muons;
    YODA::Dbn1D _n_charged,_n_total,_sphericity,_thrust,_p_total,
      _p_l,_pt,_pt2,_pt2_in,_pt2_out;
    CounterPtr  _h_weight;
    //@}

  };

  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(TASSO_1984_I195333);

}