Rivet analyses referenceCMD3_2019_I1770428$e^+e^-\to K^0_SK^0_S\pi^+\pi^-$ below 2 GeVExperiment: CMD3 (VEPP-2M) Inspire ID: 1770428 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the cross section for $e^+e^-\to K^0_SK^0_S\pi^+\pi^-$ below 2 GeV by the CMD3 experiment Source code: CMD3_2019_I1770428.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4
5namespace Rivet {
6
7
8 /// @brief CMD3 K0 K0 pi+pi-
9 class CMD3_2019_I1770428 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(CMD3_2019_I1770428);
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
25 // Book histograms
26 book(_cK0K0pippim , "TMP/K0K0pippim");
27 book( _h_pipi ,2,1,1);
28 book( _h_total,2,1,2);
29 }
30
31
32 /// Perform the per-event analysis
33 void analyze(const Event& event) {
34 const FinalState& fs = apply<FinalState>(event, "FS");
35
36 map<long,int> nCount;
37 int ntotal(0);
38 Particles pip,k0;
39 for (const Particle& p : fs.particles()) {
40 nCount[p.pid()] += 1;
41 if(p.abspid()==211)
42 pip.push_back(p);
43 else if(p.pid()==310)
44 k0.push_back(p);
45 ++ntotal;
46 }
47 if(ntotal==4 && nCount[310]==2 && nCount[211]==1 && nCount[-211]==1) {
48 _cK0K0pippim->fill();
49 FourMomentum ppipi = pip[0].momentum()+pip[1].momentum();
50 _h_pipi->fill(ppipi.mass()/MeV);
51 for(unsigned int ix=0;ix<2;++ix)
52 _h_total->fill((ppipi+k0[ix].momentum()).mass()/MeV);
53 }
54 }
55
56
57 /// Normalise histograms etc., after the run
58 void finalize() {
59 normalize(_h_pipi );
60 normalize(_h_total);
61 double fact = crossSection()/ sumOfWeights() /nanobarn;
62 double sigma = _cK0K0pippim->val()*fact;
63 double error = _cK0K0pippim->err()*fact;
64 Estimate1DPtr mult;
65 book(mult, 1, 1, 6);
66 for (auto& b : mult->bins()) {
67 if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
68 b.set(sigma, error);
69 }
70 }
71 }
72
73 /// @}
74
75
76 /// @name Histograms
77 /// @{
78 CounterPtr _cK0K0pippim;
79 Histo1DPtr _h_pipi, _h_total;
80 /// @}
81
82
83 };
84
85
86 RIVET_DECLARE_PLUGIN(CMD3_2019_I1770428);
87
88
89}
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