Rivet analyses referenceSND_2020_I1806118Cross Section for $e^+e^-\to K^+K^-\pi^0$ and $\phi\pi^0$ from threshold to 2.1 GeVExperiment: SND (VEPP-2000) Inspire ID: 1806118 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Cross section for $e^+e^-\to K^+K^-\pi^0$ between threshold and 2.1 GeV. The $\phi\pi^0$ radiative subprocess is also measured. Source code: SND_2020_I1806118.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 SND_2020_I1806118 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(SND_2020_I1806118);
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
27 // Book histograms
28 book( _nKKPi,"TMP/nKKPi" );
29 book(_nPhiPi,"TMP/nPhiPi");
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()]-=1;
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 // KK pi state
54 if(ntotal==3 && nCount[321]==1 &&
55 nCount[-321]==1 && nCount[111]==1)
56 _nKKPi->fill();
57 // phi pi state
58 const FinalState& ufs = apply<FinalState>(event, "UFS");
59 for (const Particle& p : ufs.particles(Cuts::pid==333)) {
60 if(p.children().empty()) continue;
61 map<long,int> nRes = nCount;
62 int ncount = ntotal;
63 findChildren(p,nRes,ncount);
64 if(ncount!=1) continue;
65 bool matched = true;
66 for(auto const & val : nRes) {
67 if(val.first==111) {
68 if(val.second!=1) {
69 matched = false;
70 break;
71 }
72 }
73 else if(val.second!=0) {
74 matched = false;
75 break;
76 }
77 }
78 if(matched) {
79 _nPhiPi->fill();
80 break;
81 }
82 }
83 }
84
85
86 /// Normalise histograms etc., after the run
87 void finalize() {
88 for (unsigned int ix=1;ix<3;++ix) {
89 double sigma,error;
90 if(ix==1) {
91 sigma = _nKKPi->val();
92 error = _nKKPi->err();
93 }
94 else {
95 sigma = _nPhiPi->val();
96 error = _nPhiPi->err();
97 }
98 sigma *= crossSection()/ sumOfWeights() /nanobarn;
99 error *= crossSection()/ sumOfWeights() /nanobarn;
100 Estimate1DPtr mult;
101 book(mult, ix, 1, 1);
102 for (auto& b : mult->bins()) {
103 if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
104 b.set(sigma, error);
105 }
106 }
107 }
108 }
109 /// @}
110
111
112 /// @name Histograms
113 /// @{
114 CounterPtr _nKKPi,_nPhiPi;
115 /// @}
116
117
118 };
119
120
121 RIVET_DECLARE_PLUGIN(SND_2020_I1806118);
122
123}
|