Rivet analyses referenceKLOE_2008_I791841Cross section for $\pi^+\pi^-2\pi^0$ and $2\pi^0\gamma$ near the $\phi$ massExperiment: KLOE (DAPHNE) Inspire ID: 791841 Status: VALIDATED Authors:
Beam energies: (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5); (0.5, 0.5) GeV Run details:
Measurement of the cross section for $\pi^+\pi^-2\pi^0$ and $2\pi^0\gamma$ near the $\phi$ mass. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples. Source code: KLOE_2008_I791841.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4
5namespace Rivet {
6
7
8 /// @brief e+e- -> pi+pi-2pi0 and 2pi0gamma near the phi
9 class KLOE_2008_I791841 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(KLOE_2008_I791841);
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 book(_n4pi, 1,1,1);
24 book(_n2pigamma, 2,1,1);
25 for (const string& en : _n4pi.binning().edges<0>()) {
26 const double end = std::stod(en)*MeV;
27 if (isCompatibleWithSqrtS(end)) {
28 _ecms = en;
29 break;
30 }
31 }
32 if (_ecms.empty())
33 MSG_ERROR("Beam energy incompatible with analysis.");
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39 const FinalState& fs = apply<FinalState>(event, "FS");
40
41 map<long,int> nCount;
42 for (const Particle& p : fs.particles()) {
43 nCount[p.pid()] += 1;
44 }
45 if (nCount[111]==2) {
46 if( nCount[211] == 1 && nCount[-211] == 1 ) {
47 _n4pi->fill(_ecms);
48 }
49 else if( nCount[22] == 1) {
50 _n2pigamma->fill(_ecms);
51 }
52 }
53 }
54
55
56 /// Normalise histograms etc., after the run
57 void finalize() {
58 double fact = crossSection()/ sumOfWeights() /nanobarn;
59 scale(_n4pi,fact);
60 scale(_n2pigamma,fact);
61 }
62
63 /// @}
64
65
66 /// @name Histograms
67 /// @{
68 BinnedHistoPtr<string> _n4pi,_n2pigamma;
69 string _ecms;
70 /// @}
71
72
73 };
74
75
76 RIVET_DECLARE_PLUGIN(KLOE_2008_I791841);
77
78
79}
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