Rivet analyses referenceBELLE_2008_I791660Cross section for $e^+e^-\to \Lambda_c^+\bar{\Lambda}_c^-$ below 5.4 GeV.Experiment: BELLE (KEKB) Inspire ID: 791660 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Cross section for $e^+e^-\to \Lambda_c^+\bar{\Lambda}_c^-$ below 5.4 GeV. Source code: BELLE_2008_I791660.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 BELLE_2008_I791660 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2008_I791660);
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(_nLambda, "/TMP/nLambda");
27 }
28
29 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
30 for (const Particle &child : p.children()) {
31 if(child.children().empty()) {
32 nRes[child.pid()]-=1;
33 --ncount;
34 }
35 else
36 findChildren(child,nRes,ncount);
37 }
38 }
39
40 /// Perform the per-event analysis
41 void analyze(const Event& event) {
42 const FinalState& fs = apply<FinalState>(event, "FS");
43
44 map<long,int> nCount;
45 int ntotal(0);
46 for (const Particle& p : fs.particles()) {
47 nCount[p.pid()] += 1;
48 ++ntotal;
49 }
50 const FinalState& ufs = apply<FinalState>(event, "UFS");
51
52 for(unsigned int ix=0;ix<ufs.particles().size();++ix) {
53 const Particle& p1 = ufs.particles()[ix];
54 if(abs(p1.pid())!=4122) continue;
55 map<long,int> nRes = nCount;
56 int ncount = ntotal;
57 findChildren(p1,nRes,ncount);
58 bool matched=false;
59 for(unsigned int iy=0;iy<ufs.particles().size();++iy) {
60 if(ix==iy) continue;
61 const Particle& p2 = ufs.particles()[iy];
62 if(p2.pid() != -p1.pid()) continue;
63 map<long,int> nRes2 = nRes;
64 int ncount2 = ncount;
65 findChildren(p2,nRes2,ncount2);
66 if(ncount2!=0) continue;
67 matched=true;
68 for(auto const & val : nRes2) {
69 if(val.second!=0) {
70 matched = false;
71 break;
72 }
73 }
74 if(matched) {
75 break;
76 }
77 }
78 if(matched) {
79 _nLambda->fill();
80 break;
81 }
82 }
83 }
84
85
86 /// Normalise histograms etc., after the run
87 void finalize() {
88
89 double sigma = _nLambda->val();
90 double error = _nLambda->err();
91 sigma *= crossSection()/ sumOfWeights() /nanobarn;
92 error *= crossSection()/ sumOfWeights() /nanobarn;
93 Estimate1DPtr mult;
94 book(mult, 1, 1, 1);
95 for (auto& b : mult->bins()) {
96 if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
97 b.set(sigma, error);
98 }
99 }
100 }
101
102 /// @}
103
104
105 /// @name Histograms
106 /// @{
107 CounterPtr _nLambda;
108 /// @}
109
110
111 };
112
113
114 RIVET_DECLARE_PLUGIN(BELLE_2008_I791660);
115
116
117}
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