Rivet analyses

Mass distributions in D⁺ → K⁺K⁻π⁺π⁰ decays

Experiment: BESIII (BEPC)

Inspire ID: 1808166

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 102 (2020) 5, 052006

Beams: * *

Beam energies: ANY

Run details: - Any process producting D+ mesons, originally psi(3770) decay

Measurement of the mass distributions in D⁺ → K⁺K⁻π⁺π⁰ decays by the BESIII collaboration. The data were read from the plots in the paper, and then the backgrounds given subtracted, and therefore for some points the error bars are the size of the point. Also resolution and efficiencies have not been unfolded.

Source code:`BESIII_2020_I1808166.cc`

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"

namespace Rivet {


  /// @brief D+ -> K+K-pi+pi0
  class BESIII_2020_I1808166 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2020_I1808166);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid==411);
      declare(ufs, "UFS");
      DecayedParticles DD(ufs);
      DD.addStable(PID::PI0);
      DD.addStable(PID::K0S);
      declare(DD, "DD");
      // histograms
      for (unsigned int ix=0; ix<10; ++ix) {
        book(_h[ix], 1, 1, 1+ix);
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      DecayedParticles DD = apply<DecayedParticles>(event, "DD");
      // loop over particles
      for (unsigned int ix=0; ix<DD.decaying().size(); ++ix) {
        int sign = DD.decaying()[ix].pid()/DD.decaying()[ix].abspid();
        if ( !DD.modeMatches(ix,4,mode) && !DD.modeMatches(ix,4,modeCC)) continue;
          const Particle & Kp  = DD.decayProducts()[ix].at( sign*321)[0];
          const Particle & Km  = DD.decayProducts()[ix].at(-sign*321)[0];
          const Particle & pip = DD.decayProducts()[ix].at( sign*211)[0];
          const Particle & pi0 = DD.decayProducts()[ix].at(      111)[0];
          _h[0]->fill((Kp .mom()+Km .mom()).mass());
          _h[1]->fill((Kp .mom()+pip.mom()).mass());
          _h[2]->fill((Kp .mom()+pi0.mom()).mass());
          _h[3]->fill((Km .mom()+pip.mom()).mass());
          _h[4]->fill((Km .mom()+pi0.mom()).mass());
          _h[5]->fill((pip.mom()+pi0.mom()).mass());
          _h[6]->fill((Kp .mom()+Km .mom()+pip.mom()).mass());
          _h[7]->fill((Kp .mom()+Km .mom()+pi0.mom()).mass());
          _h[8]->fill((Kp .mom()+pip.mom()+pi0.mom()).mass());
          _h[9]->fill((Km .mom()+pip.mom()+pi0.mom()).mass());
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      normalize(_h);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[10];
    const map<PdgId,unsigned int> mode   = { {321,1}, {-321,1}, { 211,1}, { 111,1} };
    const map<PdgId,unsigned int> modeCC = { {321,1}, {-321,1}, {-211,1}, { 111,1} };
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BESIII_2020_I1808166);

}

Rivet analyses

Mass distributions in D+ → K+K−π+π0 decays

Source code:BESIII_2020_I1808166.cc

Mass distributions in D⁺ → K⁺K⁻π⁺π⁰ decays

Source code:`BESIII_2020_I1808166.cc`