Rivet analyses referenceBESII_2003_I623925Mass distributions in $J/\psi\to\gamma K^+K^-$ and $J/\psi\to\gamma K_S^0K^0_S$Experiment: BESII () Inspire ID: 623925 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the kaon mass distribution in $J/\psi\to\gamma K^+K^-$ and $J/\psi\to\gamma K_S^0K^0_S$. The data were read from the plots in the paper and the backgrounds given subtracted. Source code: BESII_2003_I623925.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4#include "Rivet/Projections/DecayedParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief J/psi -> gamma K+K- KS0 KS0
10 class BESII_2003_I623925 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2003_I623925);
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 UnstableParticles ufs = UnstableParticles(Cuts::abspid==443);
24 declare(ufs, "UFS");
25 DecayedParticles PSI(ufs);
26 PSI.addStable(PID::K0S);
27 declare(PSI, "PSI");
28 // histos
29 for (unsigned int ix=0; ix<2; ++ix) {
30 book(_h[ix], 1, 1, 1+ix);
31 }
32 }
33
34
35 /// Perform the per-event analysis
36 void analyze(const Event& event) {
37 // find the J/psi decays
38 DecayedParticles PSI = apply<DecayedParticles>(event, "PSI");
39 // loop over particles
40 for (unsigned int ix=0; ix<PSI.decaying().size(); ++ix) {
41 unsigned int imode=0;
42 if (PSI.modeMatches(ix,3,mode1)) imode=0;
43 else if (PSI.modeMatches(ix,3,mode2)) imode=1;
44 else continue;
45 const Particle& gam = PSI.decayProducts()[0].at( 22)[0];
46 _h[imode]->fill((PSI.decaying()[ix].mom()-gam.mom()).mass()/GeV);
47 }
48 }
49
50
51 /// Normalise histograms etc., after the run
52 void finalize() {
53 normalize(_h, 1.0, false);
54 }
55
56 /// @}
57
58
59 /// @name Histograms
60 /// @{
61 Histo1DPtr _h[2];
62 const map<PdgId,unsigned int> mode1 = { { 321,1}, { 321,1}, { 22,1}};
63 const map<PdgId,unsigned int> mode2 = { { 310,2}, { 22,1}};
64 /// @}
65
66
67 };
68
69
70 RIVET_DECLARE_PLUGIN(BESII_2003_I623925);
71
72}
|