Rivet analyses referenceBESIII_2019_I1723934Cross section for $e^+e^-\to \omega\chi_{c0}$ at energies between 4.178 and 4.278 GeVExperiment: BESIII (BEPC) Inspire ID: 1723934 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the cross section for $e^+e^-\to \omega\chi_{c0}$ at energies between 4.178 and 4.278 GeV by the BESIII collaboration. Source code: BESIII_2019_I1723934.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 Add a short analysis description here
10 class BESIII_2019_I1723934 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2019_I1723934);
15
16
17 /// @name Analysis methods
18 //@{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 declare(FinalState(), "FS");
23 declare(UnstableParticles(), "UFS");
24 book(_nChi0, "TMP/chi0");
25 }
26
27 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
28 for( const Particle &child : p.children()) {
29 if(child.children().empty()) {
30 --nRes[child.pid()];
31 --ncount;
32 }
33 else
34 findChildren(child,nRes,ncount);
35 }
36 }
37
38 /// Perform the per-event analysis
39 void analyze(const Event& event) {
40 const FinalState& fs = apply<FinalState>(event, "FS");
41 map<long,int> nCount;
42 int ntotal(0);
43 for (const Particle& p : fs.particles()) {
44 nCount[p.pid()] += 1;
45 ++ntotal;
46 }
47 const FinalState& ufs = apply<FinalState>(event, "UFS");
48 bool matched = false;
49 for (const Particle& p : ufs.particles(Cuts::pid==10441)) {
50 if(p.children().empty()) continue;
51 map<long,int> nRes = nCount;
52 int ncount = ntotal;
53 findChildren(p,nRes,ncount);
54 for (const Particle& p2 : ufs.particles(Cuts::pid==223)) {
55 map<long,int> nRes2 = nRes;
56 int ncount2 = ncount;
57 findChildren(p2,nRes2,ncount2);
58 if(ncount2!=0) continue;
59 matched=true;
60 for(auto const & val : nRes2) {
61 if(val.second!=0) {
62 matched = false;
63 break;
64 }
65 }
66 if(matched) {
67 _nChi0->fill();
68 break;
69 }
70 }
71 if(matched) break;
72 }
73 }
74
75
76 /// Normalise histograms etc., after the run
77 void finalize() {
78
79 double fact = crossSection()/ sumOfWeights() /picobarn;
80 double sigma = _nChi0->val()*fact;
81 double error = _nChi0->err()*fact;
82 Scatter2D temphisto(refData(1, 1, 1));
83 Scatter2DPtr mult;
84 book(mult, 1, 1, 1);
85 for (size_t b = 0; b < temphisto.numPoints(); b++) {
86 const double x = temphisto.point(b).x();
87 pair<double,double> ex = temphisto.point(b).xErrs();
88 pair<double,double> ex2 = ex;
89 if(ex2.first ==0.) ex2. first=0.0001;
90 if(ex2.second==0.) ex2.second=0.0001;
91 if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
92 mult->addPoint(x, sigma, ex, make_pair(error,error));
93 }
94 else {
95 mult->addPoint(x, 0., ex, make_pair(0.,.0));
96 }
97 }
98 }
99
100 //@}
101
102
103 /// @name Histograms
104 //@{
105 CounterPtr _nChi0;
106 //@}
107
108
109 };
110
111
112 // The hook for the plugin system
113 RIVET_DECLARE_PLUGIN(BESIII_2019_I1723934);
114
115
116}
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