Rivet analyses referenceCELLO_1984_I202783Measurement of $R$ for energies between 33 and 47 GeVExperiment: CELLO (PETRA) Inspire ID: 202783 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of $R$ in $e^+e^-$ collisions for energies between 33 and 47 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: CELLO_1984_I202783.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 CELLO_1984_I202783 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(CELLO_1984_I202783);
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 // counters for R
24 book(_c_hadrons, "/TMP/sigma_hadrons");
25 book(_c_muons, "/TMP/sigma_muons");
26 }
27
28
29 /// Perform the per-event analysis
30 void analyze(const Event& event) {
31 const FinalState& fs = apply<FinalState>(event, "FS");
32
33 map<long,int> nCount;
34 int ntotal(0);
35 unsigned int nCharged(0);
36 for (const Particle& p : fs.particles()) {
37 nCount[p.pid()] += 1;
38 ++ntotal;
39 if(PID::isCharged(p.pid())) ++nCharged;
40 }
41 // mu+mu- + photons
42 if(nCount[-13]==1 and nCount[13]==1 &&
43 ntotal==2+nCount[22])
44 _c_muons->fill();
45 // everything else
46 else {
47 _c_hadrons->fill();
48 }
49
50 }
51
52
53 /// Normalise histograms etc., after the run
54 void finalize() {
55 Scatter1D R = *_c_hadrons/ *_c_muons;
56 double rval = R.point(0).x();
57 pair<double,double> rerr = R.point(0).xErrs();
58 double fact = crossSection()/ sumOfWeights() /picobarn;
59 double sig_h = _c_hadrons->val()*fact;
60 double err_h = _c_hadrons->err()*fact;
61 double sig_m = _c_muons ->val()*fact;
62 double err_m = _c_muons ->err()*fact;
63 Scatter2D temphisto(refData(2, 1, 1));
64 Scatter2DPtr hadrons;
65 book(hadrons, "sigma_hadrons");
66 Scatter2DPtr muons;
67 book(muons, "sigma_muons" );
68 Scatter2DPtr mult;
69 book(mult, 2, 1, 1);
70 for (size_t b = 0; b < temphisto.numPoints(); b++) {
71 const double x = temphisto.point(b).x();
72 pair<double,double> ex = temphisto.point(b).xErrs();
73 pair<double,double> ex2 = ex;
74 if(ex2.first ==0.) ex2. first=0.0001;
75 if(ex2.second==0.) ex2.second=0.0001;
76 if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
77 mult ->addPoint(x, rval, ex, rerr);
78 hadrons->addPoint(x, sig_h, ex, make_pair(err_h,err_h));
79 muons ->addPoint(x, sig_m, ex, make_pair(err_m,err_m));
80 }
81 else {
82 mult ->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(CELLO_1984_I202783);
103
104
105}
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