Rivet analyses referenceCMD2_1995_I406880Cross section for $e^+e^-\to$ $K^+K^-$, $K_S^0K_L^0$, $\pi^+\pi^-\pi^0$ and $\eta\gamma$ near the $\phi$ resonanceExperiment: CMD2 (VEPP-2M) Inspire ID: 406880 Status: VALIDATED Authors:
Beam energies: ANY Run details:
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 CMD2_1995_I406880 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_1995_I406880);
15
16
17 /// @name Analysis methods
18 //@{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22
23 // Initialise and register projections
24 declare(FinalState(), "FS");
25 declare(UnstableParticles(), "UFS");
26 book(_nKpKm, "TMP/KpKm");
27 book(_nK0K0, "TMP/K0K0");
28 book(_n3pi, "TMP/3pi");
29 book(_numEtaGamma, "TMP/EtaGamma");
30 }
31
32 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
33 for (const Particle &child : p.children()) {
34 if(child.children().empty()) {
35 --nRes[child.pid()];
36 --ncount;
37 }
38 else
39 findChildren(child,nRes,ncount);
40 }
41 }
42
43 /// Perform the per-event analysis
44 void analyze(const Event& event) {
45 const FinalState& fs = apply<FinalState>(event, "FS");
46
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 if(ntotal==2) {
54 if(nCount[321]==1 && nCount[-321]==1)
55 _nKpKm->fill();
56 else if(nCount[130]==1 && nCount[310]==1)
57 _nK0K0->fill();
58 }
59 else if(ntotal==3 && nCount[211] == 1 && nCount[-211] == 1 && nCount[111] == 1)
60 _n3pi->fill();
61
62 const FinalState& ufs = apply<FinalState>(event, "UFS");
63 for (const Particle& p : ufs.particles()) {
64 if(p.children().empty()) continue;
65 // find the omega
66 if(p.pid()==221) {
67 map<long,int> nRes = nCount;
68 int ncount = ntotal;
69 findChildren(p,nRes,ncount);
70 // eta pi+pi-
71 if(ncount!=1) continue;
72 bool matched = true;
73 for(auto const & val : nRes) {
74 if(val.first==22) {
75 if(val.second !=1) {
76 matched = false;
77 break;
78 }
79 }
80 else if(val.second!=0) {
81 matched = false;
82 break;
83 }
84 }
85 if(matched)
86 _numEtaGamma->fill();
87 }
88 }
89 }
90
91
92 /// Normalise histograms etc., after the run
93 void finalize() {
94 for(unsigned int ix=1;ix<5;++ix) {
95 double sigma = 0., error = 0.;
96 if(ix==1) {
97 sigma = _nKpKm->val();
98 error = _nKpKm->err();
99 }
100 else if(ix==2) {
101 sigma = _nK0K0->val();
102 error = _nK0K0->err();
103 }
104 else if(ix==3) {
105 sigma = _n3pi->val();
106 error = _n3pi->err();
107 }
108 else if(ix==4) {
109 sigma = _numEtaGamma->val();
110 error = _numEtaGamma->err();
111 }
112 sigma *= crossSection()/ sumOfWeights() /nanobarn;
113 error *= crossSection()/ sumOfWeights() /nanobarn;
114 Scatter2D temphisto(refData(1, 1, ix));
115 Scatter2DPtr mult;
116 book(mult, 1, 1, ix);
117 for (size_t b = 0; b < temphisto.numPoints(); b++) {
118 const double x = temphisto.point(b).x();
119 pair<double,double> ex = temphisto.point(b).xErrs();
120 pair<double,double> ex2 = ex;
121 if(ex2.first ==0.) ex2. first=0.0001;
122 if(ex2.second==0.) ex2.second=0.0001;
123 if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
124 mult->addPoint(x, sigma, ex, make_pair(error,error));
125 }
126 else {
127 mult->addPoint(x, 0., ex, make_pair(0.,.0));
128 }
129 }
130 }
131 }
132 //@}
133
134
135 /// @name Histograms
136 //@{
137 CounterPtr _nKpKm,_nK0K0,_n3pi,_numEtaGamma;
138 //@}
139
140
141 };
142
143
144 // The hook for the plugin system
145 RIVET_DECLARE_PLUGIN(CMD2_1995_I406880);
146
147
148}
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