Rivet analyses referenceBELLE_2004_I643565Cross section for $e^+e^-\to D^{(*)+}D^{(*)-}$ at $\sqrt{s}=10.58$GeVExperiment: BELLE (KEKB) Inspire ID: 643565 Status: VALIDATED NOHEPDATA Authors:
Beam energies: (5.3, 5.3) GeV Run details:
Cross section for $e^+e^-\to D^{(*)+}D^{(*)-}$ at $\sqrt{s}=10.58$GeV Source code: BELLE_2004_I643565.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- > D(*)+ D(*)-
10 class BELLE_2004_I643565 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2004_I643565);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 // Initialise and register projections
23 declare(FinalState(), "FS");
24 declare(UnstableParticles(Cuts::abspid==411 || Cuts::abspid==413), "UFS");
25 // histos
26 book(_h_sigma[0],1,1,2);
27 book(_h_sigma[1],1,1,5);
28 book(_h_hel ,2,1,1);
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
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 const FinalState& ufs = apply<FinalState>(event, "UFS");
54 Particle Dstar;
55 for (unsigned int ix=0;ix<ufs.particles().size();++ix) {
56 map<long,int> nRes = nCount;
57 int ncount = ntotal;
58 findChildren(ufs.particles()[ix],nRes,ncount);
59 bool matched=false;
60 for (unsigned int iy=ix+1;iy<ufs.particles().size();++iy) {
61 if (ufs.particles()[ix].pid()*ufs.particles()[iy].pid()>0) continue;
62 map<long,int> nRes2 = nRes;
63 int ncount2 = ncount;
64 findChildren(ufs.particles()[iy],nRes2,ncount2);
65 if (ncount2!=0) continue;
66 matched=true;
67 for (const auto& val : nRes2) {
68 if (val.second!=0) {
69 matched = false;
70 break;
71 }
72 }
73 if (matched) {
74 if (ufs.particles()[ix].abspid()==413 &&
75 ufs.particles()[iy].abspid()==413) {
76 _h_sigma[0]->fill("10.58"s);
77 }
78 else if (ufs.particles()[ix].abspid()==411 &&
79 ufs.particles()[iy].abspid()==413) {
80 _h_sigma[1]->fill("10.58"s);
81 Dstar = ufs.particles()[iy];
82 }
83 else if (ufs.particles()[iy].abspid()==411 &&
84 ufs.particles()[ix].abspid()==413) {
85 _h_sigma[1]->fill("10.58"s);
86 Dstar = ufs.particles()[ix];
87 }
88 break;
89 }
90 }
91 if (matched) break;
92 }
93 if (Dstar.abspid()==413 && Dstar.children().size()==2) {
94 Particle pim;
95 int sign = Dstar.pid()/Dstar.abspid();
96 if (Dstar.children()[0].pid()==sign*211 &&
97 Dstar.children()[1].pid()==sign*421) {
98 pim = Dstar.children()[0];
99 }
100 else if (Dstar.children()[1].pid()==sign*211 &&
101 Dstar.children()[0].pid()==sign*421) {
102 pim = Dstar.children()[1];
103 }
104 else {
105 return;
106 }
107 const LorentzTransform boost2 = LorentzTransform::mkFrameTransformFromBeta(Dstar.mom().betaVec());
108 FourMomentum pPim = boost2.transform(pim.mom());
109 _h_hel->fill(pPim.p3().unit().dot(Dstar.mom().p3().unit()));
110 }
111 }
112
113
114 /// Normalise histograms etc., after the run
115 void finalize() {
116 scale(_h_sigma, crossSection()/picobarn/sumOfWeights());
117 normalize(_h_hel, 1.0, false);
118 }
119
120 /// @}
121
122
123 /// @name Histograms
124 /// @{
125 BinnedHistoPtr<string> _h_sigma[2];
126 Histo1DPtr _h_hel;
127 /// @}
128
129
130 };
131
132
133 RIVET_DECLARE_PLUGIN(BELLE_2004_I643565);
134
135}
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