Rivet analyses referenceBELLE_2020_I1789775Cross section for $e^+e^-\to D_s^+D^{*-}_{s2}-\text{c.c.}$ between 4.52 and 5.6 GeVExperiment: BELLE (KEKB) Inspire ID: 1789775 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the cross section for $e^+e^-\to D_s^+D^{*-}_{s2}+\text{c.c.}$ times the branching ratio for $D^{*-}_{s2}\to \bar{D}^0K^-$ for centre-of-mass energies between 4.52 and 5.6 GeV by the BELLE collaboration. Source code: BELLE_2020_I1789775.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- -> Ds D_s2
10 class BELLE_2020_I1789775 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2020_I1789775);
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(), "UFS");
25
26 // Book histograms
27 book(_c_Ds ,"/TMP/c_Ds" );
28 }
29
30 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
31 for(const Particle &child : p.children()) {
32 if(child.children().empty()) {
33 nRes[child.pid()]-=1;
34 --ncount;
35 }
36 else
37 findChildren(child,nRes,ncount);
38 }
39 }
40
41 /// Perform the per-event analysis
42 void analyze(const Event& event) {
43 const FinalState& fs = apply<FinalState>(event, "FS");
44 // total analyse final state
45 map<long,int> nCount;
46 int ntotal(0);
47 for (const Particle& p : fs.particles()) {
48 nCount[p.pid()] += 1;
49 ++ntotal;
50 }
51 // unstable charm analysis
52 Particles ds = apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid==431 or Cuts::abspid==435);
53 for(unsigned int ix=0;ix<ds.size();++ix) {
54 const Particle& p1 = ds[ix];
55 int id1 = abs(p1.pid());
56 // check fs
57 bool fs = true;
58 for (const Particle & child : p1.children()) {
59 if(child.pid()==p1.pid()) {
60 fs = false;
61 break;
62 }
63 }
64 if(!fs) continue;
65 // find the children
66 map<long,int> nRes = nCount;
67 int ncount = ntotal;
68 findChildren(p1,nRes,ncount);
69 bool matched=false;
70 int sign = p1.pid()/id1;
71 for(unsigned int iy=ix+1;iy<ds.size();++iy) {
72 const Particle& p2 = ds[iy];
73 fs = true;
74 for (const Particle & child : p2.children()) {
75 if(child.pid()==p2.pid()) {
76 fs = false;
77 break;
78 }
79 }
80 if(!fs) continue;
81 if(p2.pid()/abs(p2.pid())==sign) continue;
82 int id2 = abs(p2.pid());
83 if(!p2.parents().empty() && p2.parents()[0].pid()==p1.pid())
84 continue;
85 map<long,int> nRes2 = nRes;
86 int ncount2 = ncount;
87 findChildren(p2,nRes2,ncount2);
88 if(ncount2!=0) continue;
89 matched=true;
90 for(auto const & val : nRes2) {
91 if(val.second!=0) {
92 matched = false;
93 break;
94 }
95 }
96 if(matched) {
97 if((id1==431 && id2==435) || (id1==435 && id2==431)) {
98 Particle Ds2 = id1==435 ? p1 : p2;
99 matched = false;
100 if(Ds2.children().size()!=2) continue;
101 if(Ds2.pid()==435 &&
102 ((Ds2.children()[0].pid()==421 && Ds2.children()[1].pid()==321) ||
103 (Ds2.children()[1].pid()==421 && Ds2.children()[0].pid()==321) ))
104 matched = true;
105 else if (Ds2.pid()==-435 &&
106 ((Ds2.children()[0].pid()==-421 && Ds2.children()[1].pid()==-321) ||
107 (Ds2.children()[1].pid()==-421 && Ds2.children()[0].pid()==-321) ))
108 matched = true;
109 if(matched) {
110 _c_Ds->fill();
111 break;
112 }
113 }
114 }
115 }
116 if(matched) break;
117 }
118 }
119
120
121 /// Normalise histograms etc., after the run
122 void finalize() {
123 double fact = crossSection()/ sumOfWeights()/picobarn;
124 double sigma = _c_Ds->val()*fact;
125 double error = _c_Ds->err()*fact;
126 Estimate1DPtr mult;
127 book(mult, 1, 1, 1);
128 for (auto& b : mult->bins()) {
129 if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
130 b.set(sigma, error);
131 }
132 }
133 }
134
135 /// @}
136
137
138 /// @name Histograms
139 /// @{
140 CounterPtr _c_Ds;
141 /// @}
142
143
144 };
145
146
147 RIVET_DECLARE_PLUGIN(BELLE_2020_I1789775);
148
149}
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