Rivet analyses referenceBELLE_2022_I2173361$e^+e^-\to\Sigma^0\bar{\Sigma}^0$ and $\Sigma^+\bar{\Sigma}^-$ for $\sqrt{s}=2.379-3$ GeVExperiment: BELLE (KEKB) Inspire ID: 2173361 Status: VALIDATED NOHEPDATA SINGLEWEIGHT Authors:
Beam energies: ANY Run details:
Measurement of the cross section for $e^+e^-\to\Sigma^0\bar{\Sigma}^0$ and $\Sigma^+\bar{\Sigma}^-$ for $\sqrt{s}=2.379-3$ GeV by BELLE using raditive events. Beam energy must be specified as analysis option "ENERGY" when rivet-merging samples. Source code: BELLE_2022_I2173361.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/UnstableParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief e+ e- > Sigma Sigmabar
10 class BELLE_2022_I2173361 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2022_I2173361);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 // projections
23 declare(FinalState(), "FS");
24 declare(UnstableParticles(Cuts::abspid==3222 || Cuts::abspid==3212), "UFS");
25 // histos
26 for (unsigned int ix=0; ix<2; ++ix) {
27 book(_sigma[ix],"TMP/c_"+toString(ix+1),refData(ix+1, 1, 1));
28 }
29 }
30
31 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
32 for (const Particle &child : p.children()) {
33 if (child.children().empty()) {
34 nRes[child.pid()]-=1;
35 --ncount;
36 }
37 else {
38 findChildren(child,nRes,ncount);
39 }
40 }
41 }
42
43 /// Perform the per-event analysis
44 void analyze(const Event& event) {
45 const FinalState& fs = apply<FinalState>(event, "FS");
46 // total hadronic and muonic cross sections
47 map<long,int> nCount;
48 int ntotal(0);
49 for (const Particle& p : fs.particles()) {
50 nCount[p.pid()] += 1;
51 ++ntotal;
52 }
53 // find the Sigmas
54 const FinalState& ufs = apply<UnstableParticles>(event, "UFS");
55 for (unsigned int ix=0; ix<ufs.particles().size(); ++ix) {
56 const Particle& p1 = ufs.particles()[ix];
57 bool matched = false;
58 // check fs
59 bool fs = true;
60 for (const Particle& child : p1.children()) {
61 if (child.pid()==p1.pid()) {
62 fs = false;
63 break;
64 }
65 }
66 if (!fs) continue;
67 // find the children
68 map<long,int> nRes = nCount;
69 int ncount = ntotal;
70 findChildren(p1,nRes,ncount);
71 for (unsigned int iy=ix+1;iy<ufs.particles().size();++iy) {
72 const Particle& p2 = ufs.particles()[iy];
73 if (p2.pid() != -p1.pid()) continue;
74 // check fs
75 bool fs = true;
76 for (const Particle & child : p2.children()) {
77 if (child.pid()==p2.pid()) {
78 fs = false;
79 break;
80 }
81 }
82 if (!fs) continue;
83 map<long,int> nRes2 = nRes;
84 int ncount2 = ncount;
85 findChildren(p2,nRes2,ncount2);
86 if (ncount2!=0) continue;
87 matched=true;
88 for (const auto& val : nRes2) {
89 if (val.second!=0) {
90 matched = false;
91 break;
92 }
93 }
94 if (matched) {
95 if(abs(p1.pid())==3212) _sigma[0]->fill(sqrtS());
96 else if (abs(p1.pid())==3222) _sigma[1]->fill(sqrtS());
97 break;
98 }
99 }
100 if (matched) break;
101 }
102 }
103
104
105 /// Normalise histograms etc., after the run
106 void finalize() {
107 const double fact = crossSection()/ sumOfWeights() /picobarn;
108 for(unsigned int iy=0;iy<2;++iy) {
109 scale(_sigma[iy], fact);
110 Estimate1DPtr tmp;
111 book(tmp, iy+1, 1, 1);
112 barchart(_sigma[iy], tmp);
113 }
114 }
115
116 /// @}
117
118
119 /// @name Histograms
120 /// @{
121 Histo1DPtr _sigma[2];
122 /// @}
123
124
125 };
126
127
128 RIVET_DECLARE_PLUGIN(BELLE_2022_I2173361);
129
130}
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