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Rivet analyses reference

BABAR_2006_I709730

Cross section for $e^+e^-\to$ $3\pi^+3\pi^-$, $2\pi^+2\pi^-2\pi^0$, $2\pi^+2\pi^-K^+K^-$
Experiment: BABAR (PEP-II)
Inspire ID: 709730
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Phys.Rev. D73.052003
Beams: e+ e-
Beam energies: (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2) GeV
Run details:
  • e+ e- to hadrons

Cross sections for $3\pi^+3\pi^-$, $2\pi^+2\pi^-2\pi^0$ and $2\pi^+2\pi^-K^+K^-$ measured by BaBar using radiative return. Useful to compare hadronization and other non-perturbative models at low energies between 1.3 and 4.5 GeV. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples.

Source code: BABAR_2006_I709730.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- -> 3pi+3pi-, 2pi+pi-2pi0, 2pi+pi-K+K-
 9  class BABAR_2006_I709730 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2006_I709730);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24      for(unsigned int ix=0;ix<3;++ix) {
25        book(_sigma[ix],1+ix,1,1);
26        for (const string& en : _sigma[ix].binning().edges<0>()) {
27          const double end = std::stod(en)*GeV;
28          if (isCompatibleWithSqrtS(end)) {
29            _ecms[ix] = en;
30            break;
31          }
32        }
33      }
34      if (_ecms[0].empty() && _ecms[1].empty() && _ecms[2].empty())
35        MSG_ERROR("Beam energy incompatible with analysis.");
36    }
37    
38
39    /// Perform the per-event analysis
40    void analyze(const Event& event) {
41      const FinalState& fs = apply<FinalState>(event, "FS");
42
43      map<long,int> nCount;
44      int ntotal(0);
45      for (const Particle& p : fs.particles()) {
46	nCount[p.pid()] += 1;
47	++ntotal;
48      }
49
50      if(ntotal!=6) vetoEvent;
51      if(nCount[-211]==3 && nCount[211]==3) {
52	if(!_ecms[0].empty()) _sigma[0]->fill(_ecms[0]);
53      }
54      else if(nCount[-211]==2 && nCount[211]==2 && nCount[111]==2) {
55	if(!_ecms[1].empty()) _sigma[1]->fill(_ecms[1]);
56      }
57      else if(nCount[-211]==2 && nCount[211]==2 &&
58              nCount[321]==1 && nCount[-321]==1) {
59	if(!_ecms[2].empty()) _sigma[2]->fill(_ecms[2]);
60      }
61    }
62
63
64    /// Normalise histograms etc., after the run
65    void finalize() {
66      double fact = crossSection()/ sumOfWeights() /nanobarn;
67      for(unsigned int ix=0; ix<3; ++ix)
68        scale(_sigma[ix],fact);
69    }
70
71    /// @}
72
73    // just count the number of events of the types we're looking for
74    BinnedHistoPtr<string> _sigma[3];
75    string _ecms[3];
76  };
77
78
79  RIVET_DECLARE_PLUGIN(BABAR_2006_I709730);
80
81
82}