Rivet analyses referenceARGUS_1987_I248680γγ→K∗0ˉK∗0 between 1.6 and 3.5 GeVExperiment: ARGUS (DORIS) Inspire ID: 248680 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the differential cross section for γγ→K∗0ˉK∗0 for 1.6GeV<W<3.5GeV. The cross section is measured as a function of the centre-of-mass energy of the photonic collision using the K+K−π+π− final state. Source code: ARGUS_1987_I248680.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 gamma gamma -> K*0K*0
10 class ARGUS_1987_I248680 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_1987_I248680);
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 // book histos
26 if (inRange(sqrtS()/GeV,1.6,3.5)) {
27 for (unsigned int ix=0; ix<9; ++ix) {
28 book(_nMeson[ix],"TMP/nMeson_"+toString(ix+1));
29 }
30 }
31 else {
32 throw Error("Invalid CMS energy for ARGUS_1987_I248680");
33 }
34 }
35
36 void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
37 for (const Particle& child : p.children()) {
38 if (child.children().empty()) {
39 nRes[child.pid()]-=1;
40 --ncount;
41 }
42 else {
43 findChildren(child,nRes,ncount);
44 }
45 }
46 }
47
48 /// Perform the per-event analysis
49 void analyze(const Event& event) {
50 const FinalState& fs = apply<FinalState>(event, "FS");
51 // find the final-state particles
52 map<long,int> nCount;
53 int ntotal(0);
54 for (const Particle& p : fs.particles()) {
55 nCount[p.pid()] += 1;
56 ++ntotal;
57 }
58 // find any K* mesons
59 int ires=-1;
60 const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
61 Particles Kstar=ufs.particles(Cuts::abspid==313);
62 for (unsigned int ix=0;ix<Kstar.size();++ix) {
63 if(Kstar[ix].children().empty()) continue;
64 map<long,int> nRes=nCount;
65 int ncount = ntotal;
66 findChildren(Kstar[ix],nRes,ncount);
67 bool matched=false;
68 // K*K*
69 for (unsigned int iy=ix+1; iy<Kstar.size(); ++iy) {
70 if (Kstar[iy].children().empty()) continue;
71 if (Kstar[ix].pid()!=-Kstar[iy].pid()) continue;
72 map<long,int> nRes2=nRes;
73 int ncount2 = ncount;
74 findChildren(Kstar[iy],nRes2,ncount2);
75 if (ncount2 !=0 ) continue;
76 matched = true;
77 for (const auto& val : nRes2) {
78 if (val.second!=0) {
79 matched = false;
80 break;
81 }
82 }
83 if (matched) {
84 break;
85 }
86 }
87 if (matched) {
88 _nMeson[1]->fill();
89 ires=7;
90 break;
91 }
92 int sign = Kstar[ix].pid()/Kstar[ix].abspid();
93 // three body intermediate states
94 if (ncount==2) {
95 // K*0 K- pi+ +ccd
96 matched=true;
97 for (const auto& val : nRes) {
98 if (val.first==sign*211 || val.first==-sign*321) {
99 if (val.second!=1) {
100 matched = false;
101 break;
102 }
103 }
104 else {
105 if (val.second!=0) {
106 matched = false;
107 break;
108 }
109 }
110 }
111 if(matched) {
112 _nMeson[2]->fill();
113 ires=6;
114 break;
115 }
116 }
117 }
118 // look for phi modes
119 for (const Particle& p : ufs.particles(Cuts::pid==PID::PHI)) {
120 if (p.children().empty()) continue;
121 map<long,int> nRes=nCount;
122 int ncount = ntotal;
123 findChildren(p,nRes,ncount);
124 if (ncount==2) {
125 bool matched=true;
126 for (const auto& val : nRes) {
127 if (abs(val.first)==211) {
128 if (val.second!=1) {
129 matched = false;
130 break;
131 }
132 }
133 else {
134 if (val.second!=0) {
135 matched = false;
136 break;
137 }
138 }
139 }
140 if (matched) {
141 ires=8;
142 break;
143 }
144 }
145 }
146 // 4 meson modes
147 if (ntotal==4 &&
148 nCount[PID::KPLUS ]==1 && nCount[PID::KMINUS ]==1 &&
149 nCount[PID::PIPLUS]==1 && nCount[PID::PIMINUS]==1 ) {
150 _nMeson[0]->fill();
151 _nMeson[4]->fill();
152 if (ires<0) {
153 _nMeson[3]->fill();
154 _nMeson[5]->fill();
155 }
156 else _nMeson[ires]->fill();
157 }
158 }
159
160
161 /// Normalise histograms etc., after the run
162 void finalize() {
163 scale(_nMeson, crossSection()/nanobarn/sumOfWeights());
164 // loop over tables in paper
165 for (unsigned int ih=1; ih<5; ++ih) {
166 for (unsigned int iy=1; iy<2; ++iy) {
167 unsigned int iloc=ih+iy-2;
168 assert(iloc<=8);
169 BinnedEstimatePtr<string> mult;
170 book(mult, ih, 1, iy);
171 for (auto& b : mult->bins()) {
172 if (isCompatibleWithSqrtS(std::stod(b.xEdge())/GeV)) {
173 b.setVal(_nMeson[iloc]->val());
174 b.setErr(_nMeson[iloc]->err());
175 }
176 }
177 }
178 }
179 for (unsigned int iy=1; iy<6; ++iy) {
180 unsigned int iloc=3+iy;
181 assert(iloc<=8);
182 Estimate1DPtr mult;
183 book(mult, 5, 1, iy);
184 for (auto& b : mult->bins()) {
185 if (inRange(sqrtS(), b.xMin(), b.xMax())) {
186 b.setVal(_nMeson[iloc]->val());
187 b.setErr(_nMeson[iloc]->err());
188 }
189 }
190 }
191 }
192
193 /// @}
194
195
196 /// @name Histograms
197 /// @{
198 CounterPtr _nMeson[9];
199 /// @}
200
201
202 };
203
204
205 RIVET_DECLARE_PLUGIN(ARGUS_1987_I248680);
206
207}
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