rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

ARGUS_2000_I511512

$\gamma\gamma\to K^{*0}\bar{K}^{*0}\ \text{and}\ K^{*+}K^{*-}$ between 1.5 and 3.0 GeV
Experiment: ARGUS (DORIS)
Inspire ID: 511512
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Eur.Phys.J.C 16 (2000) 435-444
Beams: 22 22
Beam energies: ANY
Run details:
  • gamma gamma to hadrons, K0S and pi0 mesons must be set stable

Measurement of the differential cross section for $\gamma\gamma\to K^{*0}\bar{K}^{*0}\ \text{and} K^{*+}K^{*-}$ for $1.5 \text{GeV} < W < 3.0 \text{GeV}$. The cross section is measured as a function of the centre-of-mass energy of the photonic collision using a range of final states.

Source code: ARGUS_2000_I511512.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*K*
 10  class ARGUS_2000_I511512 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(ARGUS_2000_I511512);
 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,1.5,3.0)) {
 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_2000_I511512");
 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
 49    /// Perform the per-event analysis
 50    void analyze(const Event& event) {
 51      const FinalState& fs = apply<FinalState>(event, "FS");
 52      // find the final-state particles
 53      map<long,int> nCount;
 54      int ntotal(0);
 55      for (const Particle& p : fs.particles()) {
 56        nCount[p.pid()] += 1;
 57        ++ntotal;
 58      }
 59      if(ntotal==4) {
 60        if (nCount[PID::KPLUS]==1 && nCount[PID::KMINUS]==1 &&
 61            nCount[PID::PIPLUS]==1 && nCount[PID::PIMINUS]==1) {
 62          _nMeson[6]->fill();
 63        }
 64        else if (nCount[PID::K0S]==2 &&
 65                 nCount[PID::PIPLUS]==1 && nCount[PID::PIMINUS]==1) {
 66          _nMeson[8]->fill();
 67        }
 68        else if (nCount[PID::K0S]==1 && nCount[PID::PI0]==1 &&
 69               ((nCount[PID::KPLUS ]==1 && nCount[PID::PIMINUS]==1) ||
 70                (nCount[PID::KMINUS]==1 && nCount[PID::PIPLUS ]==1))) {
 71          _nMeson[7]->fill();
 72        }
 73
 74      }
 75      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
 76      // find any K* mesons
 77      Particles Kstar=ufs.particles(Cuts::abspid==313 or Cuts::abspid==323);
 78      for (unsigned int ix=0;ix<Kstar.size();++ix) {
 79       	if(Kstar[ix].children().empty()) continue;
 80       	map<long,int> nRes=nCount;
 81       	int ncount = ntotal;
 82       	findChildren(Kstar[ix],nRes,ncount);
 83        int sign = Kstar[ix].pid()/Kstar[ix].abspid();
 84        // three body intermediate states
 85        if (ncount==2) {
 86          // K*0 K- pi+ +ccd
 87          if (Kstar[ix].abspid()==313) {
 88            bool matched=true;
 89            for (const auto& val : nRes) {
 90              if (val.first==sign*211 || val.first==-sign*321) {
 91                if(val.second!=1) {
 92                  matched = false;
 93                  break;
 94                }
 95              }
 96              else {
 97                if(val.second!=0) {
 98                  matched = false;
 99                  break;
100                }
101              }
102            }
103            if(matched) _nMeson[3]->fill();
104          }
105          else {
106            bool matched=false;
107            // K*+ K0S pi- + cc
108            for(auto const & val : nRes) {
109              if (val.first==-sign*211 || val.first==PID::K0S) {
110                if(val.second!=1) {
111                  matched = false;
112                  break;
113                }
114              }
115              else {
116                if(val.second!=0) {
117                  matched = false;
118                  break;
119                }
120              }
121            }
122            if (matched) _nMeson[4]->fill();
123            else {
124              // K*+ K- pi0 +cc
125              matched=false;
126              for (auto const & val : nRes) {
127                if (val.first==-sign*321 || val.first==PID::PI0) {
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) _nMeson[5]->fill();
141            }
142          }
143        }
144
145        // K*K*
146        for (unsigned int iy=ix+1;iy<Kstar.size();++iy) {
147          if (Kstar[iy].children().empty()) continue;
148          if (Kstar[ix].pid()!=-Kstar[iy].pid()) continue;
149          map<long,int> nRes2=nRes;
150          int ncount2 = ncount;
151          findChildren(Kstar[iy],nRes2,ncount2);
152          if (ncount2 !=0 ) continue;
153          bool matched2 = true;
154          for (auto const & val : nRes2) {
155            if (val.second!=0) {
156              matched2 = false;
157              break;
158            }
159          }
160          if (matched2) {
161            if (Kstar[ix].abspid()==313) {
162              _nMeson[0]->fill();
163            }
164            else {
165              _nMeson[1]->fill();
166            }
167            break;
168          }
169        }
170      }
171      // finally the rho phi intermediate states
172      for (const Particle & p1 : ufs.particles(Cuts::pid==PID::RHO0)) {
173       	if(p1.children().empty()) continue;
174       	map<long,int> nRes=nCount;
175       	int ncount = ntotal;
176       	findChildren(p1,nRes,ncount);
177        for (const Particle & p2 : ufs.particles(Cuts::pid==PID::PHI)) {
178          if (p2.children().empty()) continue;
179          map<long,int> nRes2=nRes;
180          int ncount2 = ncount;
181          findChildren(p2,nRes2,ncount2);
182          if (ncount2 !=0 ) continue;
183          bool matched = true;
184          for (auto const & val : nRes2) {
185            if (val.second!=0) {
186              matched = false;
187              break;
188            }
189          }
190          if (matched) {
191            _nMeson[2]->fill();
192            break;
193          }
194        }
195      }
196    }
197
198
199    /// Normalise histograms etc., after the run
200    void finalize() {
201      scale(_nMeson, crossSection()/nanobarn/sumOfWeights());
202      // loop over tables in paper
203      for (unsigned int ih=3; ih<11; ++ih) {
204        unsigned int imax=5;
205        if (ih==6 || ih==9 || ih==10) imax=3;
206        else if (ih==7 || ih==8)  imax=4;
207        for (unsigned int iy=1; iy<imax; ++iy) {
208          unsigned int iloc=1000;
209          // K*0 K*bar0
210          if ((iy==1 && (ih==3||ih==4||ih==5||ih==9||ih==10)) ||
211              (iy==2&&ih==6)) {
212            iloc=0;
213          }
214          // K*+ K*-
215          else if ( (iy==1 && (ih==6 || ih==8)) ||
216              (iy==2 && (ih==9 || ih==10))) {
217            iloc=1;
218          }
219          // rho phi
220          else if(iy==3 && (ih>=3&&ih<=5)) {
221            iloc=2;
222          }
223          // K*0 K- pi+ + cc
224          else if(iy==2 && (ih>=3&&ih<=5)) {
225            iloc=3;
226          }
227          // K+K-pi+pi-
228          else if(iy==4 && (ih>=3&&ih<=5)) {
229            iloc=6;
230          }
231          // K*+ K0S pi-+cc
232          else if( (ih==7&&iy==1) || (ih==8&&iy==2)) {
233            iloc=4;
234          }
235          // K*+ K- pi0 +cc
236          else if(ih==7&&iy==2) {
237            iloc=5;
238          }
239          // KS0 K+ pi- pi0 +cc
240          else if(ih==7&&iy==3) {
241            iloc=7;
242          }
243          // KS0 KS0 pi+ pi-
244          else if(ih==8&&iy==3) {
245            iloc=8;
246          }
247          assert(iloc<=8);
248          Estimate1DPtr mult;
249          book(mult, ih, 1, iy);
250          for (auto& b : mult->bins()) {
251            if (inRange(sqrtS(), b.xMin(), b.xMax())) {
252              b.setVal(_nMeson[iloc]->val());
253              b.setErr(_nMeson[iloc]->err());
254            }
255          }
256        }
257      }
258      // finally the ratio K*+/K*0
259      if (_nMeson[0]->numEntries()>0) {
260        Estimate0D R = *_nMeson[1]/ *_nMeson[0];
261        Estimate1DPtr mult;
262        book(mult, 11, 1, 1);
263        for (auto& b : mult->bins()) {
264          if (isCompatibleWithSqrtS(b.xMid())) {
265            b.setVal(R.val());
266            b.setErr(R.err());
267          }
268        }
269      }
270    }
271
272    /// @}
273
274
275    /// @name Histograms
276    /// @{
277    CounterPtr _nMeson[9];
278    /// @}
279
280
281  };
282
283
284  RIVET_DECLARE_PLUGIN(ARGUS_2000_I511512);
285
286}