Rivet analyses referenceBESII_2005_I663288Mass distributions in $J/\psi\to\phi\pi^+\pi^+$ and $\phi K^+K^-$Experiment: BESII (BEPC) Inspire ID: 663288 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Mass distributions in $J/\psi\to\phi\pi^+\pi^+$ and $\phi K^+K^-$. The data were read from the figures in the paper and are not corrected for acceptance. Source code: BESII_2005_I663288.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 -> phi pi+pi- K+K-
10 class BESII_2005_I663288 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESII_2005_I663288);
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(333);
27 declare(PSI, "PSI");
28 // histograms
29 for (unsigned int ix=0; ix<2; ++ix) {
30 for (unsigned int iy=0; iy<2; ++iy) {
31 book(_h_mass[ix][iy], 1+ix, 1, 1+iy);
32 }
33 }
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39 // J/psi decay products
40 DecayedParticles PSI = apply<DecayedParticles>(event, "PSI");
41 if (PSI.decaying().size()!=1) vetoEvent;
42 unsigned int imode=0;
43 if (PSI.modeMatches(0,3,mode1)) imode=0;
44 else if (PSI.modeMatches(0,3,mode2)) imode=1;
45 else vetoEvent;
46 unsigned int iMeson = imode == 0 ? 211 : 321;
47 const Particle & Mp = PSI.decayProducts()[0].at( iMeson)[0];
48 const Particle & Mm = PSI.decayProducts()[0].at(-iMeson)[0];
49 const Particle & phi = PSI.decayProducts()[0].at( 333)[0];
50 // mass histograms
51 FourMomentum pX = Mp.momentum()+Mm.momentum();
52 const double mX = pX.mass();
53 _h_mass[imode][0]->fill(mX/GeV);
54 _h_mass[imode][1]->fill((Mp.momentum()+phi.momentum()).mass()/GeV);
55 _h_mass[imode][1]->fill((Mm.momentum()+phi.momentum()).mass()/GeV);
56 }
57
58
59 /// Normalise histograms etc., after the run
60 void finalize() {
61 for (unsigned int ix=0; ix<2; ++ix) {
62 normalize(_h_mass[ix], 1.0, false);
63 }
64 }
65
66 /// @}
67
68
69 /// @name Histograms
70 /// @{
71 Histo1DPtr _h_mass[2][2];
72 const map<PdgId,unsigned int> mode1 = { { 333,1}, { 211,1},{-211,1}};
73 const map<PdgId,unsigned int> mode2 = { { 333,1}, { 321,1},{-321,1}};
74 /// @}
75
76
77 };
78
79
80 RIVET_DECLARE_PLUGIN(BESII_2005_I663288);
81
82}
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