Rivet analyses referenceTOPAZ_1990_I283003Measurement of $R$ for energies between 50 and 61.4 GeVExperiment: TOPAZ (Tristan) Inspire ID: 283003 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of $R$ in $e^+e^-$ collisions by TOPAZ for energies between 50 and 61.4 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: TOPAZ_1990_I283003.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 TOPAZ_1990_I283003 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(TOPAZ_1990_I283003);
14
15
16 /// @name Analysis methods
17 //@{
18
19 /// Book histograms and initialise projections before the run
20 void init() {
21 // Initialise and register projections
22 declare(FinalState(), "FS");
23
24 // Book histograms
25 book(_c_hadrons, "/TMP/sigma_hadrons");
26 book(_c_muons, "/TMP/sigma_muons");
27 }
28
29
30 /// Perform the per-event analysis
31 void analyze(const Event& event) {
32 const FinalState& fs = apply<FinalState>(event, "FS");
33
34 map<long,int> nCount;
35 int ntotal(0);
36 for (const Particle& p : fs.particles()) {
37 nCount[p.pid()] += 1;
38 ++ntotal;
39 }
40 // mu+mu- + photons
41 if(nCount[-13]==1 and nCount[13]==1 &&
42 ntotal==2+nCount[22])
43 _c_muons->fill();
44 // everything else
45 else
46 _c_hadrons->fill();
47 }
48
49
50 /// Normalise histograms etc., after the run
51 void finalize() {
52 Scatter1D R = *_c_hadrons/ *_c_muons;
53 double rval = R.point(0).x();
54 pair<double,double> rerr = R.point(0).xErrs();
55 double fact = crossSection()/ sumOfWeights() /picobarn;
56 double sig_h = _c_hadrons->val()*fact;
57 double err_h = _c_hadrons->err()*fact;
58 double sig_m = _c_muons ->val()*fact;
59 double err_m = _c_muons ->err()*fact;
60 Scatter2D temphisto(refData(1, 1, 1));
61 Scatter2DPtr hadrons;
62 book(hadrons, "sigma_hadrons");
63 Scatter2DPtr muons;
64 book(muons, "sigma_muons" );
65 Scatter2DPtr mult;
66 book(mult, 1, 1, 1);
67 for (size_t b = 0; b < temphisto.numPoints(); b++) {
68 const double x = temphisto.point(b).x();
69 pair<double,double> ex = temphisto.point(b).xErrs();
70 pair<double,double> ex2 = ex;
71 if(ex2.first ==0.) ex2. first=0.0001;
72 if(ex2.second==0.) ex2.second=0.0001;
73 if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
74 mult ->addPoint(x, rval, ex, rerr);
75 hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
76 muons ->addPoint(x, sig_m, ex, make_pair(err_m,err_m));
77 }
78 else {
79 mult ->addPoint(x, 0., ex, make_pair(0.,.0));
80 hadrons->addPoint(x, 0., ex, make_pair(0.,.0));
81 muons ->addPoint(x, 0., ex, make_pair(0.,.0));
82 }
83 }
84 }
85
86 //@}
87
88
89 /// @name Histograms
90 //@{
91 CounterPtr _c_hadrons, _c_muons;
92 //@}
93
94 };
95
96
97 // The hook for the plugin system
98 RIVET_DECLARE_PLUGIN(TOPAZ_1990_I283003);
99
100
101}
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