Rivet analyses reference

BESIII_2023_I2693763

Mads distributions in $\psi(2S)\to\phi K^0_SK^0_S$
Experiment: BESIII (BEPC)
Inspire ID: 2693763
Status: VALIDATED NOHEPDATA
Authors:

Peter Richardson

References:

Phys.Rev.D 108 (2023) 5, 052001
arXiv: 2303.08317

Beams: * *
Beam energies: ANY
Run details:

Any process producing psi(2S), originally e+e-

Measurement of mass distributions in $\psi(2S)\to\phi K^0_SK^0_S$ by BES. N.B. data read from plots and may not be corrected, no difference between $K_{S1}^0$ and $K^0_{S2}$ so these are symeterised.

Source code: BESIII_2023_I2693763.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 psi(2S) -> phi KS0 KS0
10  class BESIII_2023_I2693763 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2023_I2693763);
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::pid==100443);
24      declare(ufs, "UFS");
25      DecayedParticles psi2S(ufs);
26      psi2S.addStable(PID::PI0);
27      psi2S.addStable(PID::K0S);
28      psi2S.addStable(PID::ETA);
29      psi2S.addStable(PID::ETAPRIME);
30      psi2S.addStable(PID::PHI);
31      declare(psi2S, "psi2S");
32      // histograms
33      for (unsigned int ix=0; ix<3; ++ix) {
34	      book(_h[ix], 1, 1, 1+ix);
35      }
36      book(_dalitz, "dalitz" ,50,2.,11.,50,2.,11.);
37    }
38
39
40    /// Perform the per-event analysis
41    void analyze(const Event& event) {
42      // define the decay mode
43      DecayedParticles psi2S = apply<DecayedParticles>(event, "psi2S");
44      // loop over particles
45      for (unsigned int ix=0; ix<psi2S.decaying().size(); ++ix) {
46        if (!psi2S.modeMatches(ix,3,mode)) continue;
47        const Particles& K0  = psi2S.decayProducts()[ix].at(310);
48        const Particle & phi = psi2S.decayProducts()[ix].at(333)[0];
49        double m2Kphi[2]={(K0[0].mom()+phi.mom()).mass2(), (K0[1].mom()+phi.mom()).mass2()};
50        for (unsigned int ix=0; ix<2; ++ix) {
51          const double mKo = sqrt(m2Kphi[ix]);
52          _h[0]->fill(mKo);
53          _h[1]->fill(mKo);
54        }
55        _h[2]->fill((K0[0].mom()+K0[1].mom()).mass());
56        _dalitz->fill(m2Kphi[0],m2Kphi[1]);
57        _dalitz->fill(m2Kphi[1],m2Kphi[0]);
58      }
59    }
60
61
62    /// Normalise histograms etc., after the run
63    void finalize() {
64      normalize(_h, 1.0, false);
65      normalize(_dalitz);
66    }
67
68    /// @}
69
70
71    /// @name Histograms
72    /// @{
73    Histo1DPtr _h[3];
74    Histo2DPtr _dalitz;
75    const map<PdgId,unsigned int> mode = { { 310,2},{ 333,1}};
76    /// @}
77
78
79  };
80
81
82  RIVET_DECLARE_PLUGIN(BESIII_2023_I2693763);
83
84}