Rivet analyses

Hadronic mass in Ds+ → π0π0e+νe

Experiment: BESIII (BEPC)

Inspire ID: 2038523

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 105 (2022) 3, L031101

Beams: * *

Beam energies: ANY

Run details: - Any process producing Ds+

Measurement of the hadronic mass in Ds+ → π0π0e+νe by BES-III. N.B. the plots where read from the paper and may not have been corrected for acceptance.

Source code:BESIII_2022_I2038523.cc

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

namespace Rivet {


  /// @brief D_s+ -> pi0 pi0 e+ nu_e
  class BESIII_2022_I2038523 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2038523);


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

    /// Book histograms and initialise projections before the run
    void init() {
      UnstableParticles ufs = UnstableParticles(Cuts::pid==431);
      declare(ufs, "UFS");
      DecayedParticles DD(ufs);
      DD.addStable(PID::PI0);
      DD.addStable(PID::K0S);
      DD.addStable(PID::ETA);
      DD.addStable(PID::ETAPRIME);
      declare(DD, "DD");
      book(_h,1,1,1);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId,unsigned int> & mode = { { 111,2}, {-11,1}, { 12,1}};
      DecayedParticles DD = apply<DecayedParticles>(event, "DD");
      // loop over particles
      for(unsigned int ix=0;ix<DD.decaying().size();++ix) {
    if(!DD.modeMatches(ix,4,mode)) continue;
    const Particles & pi0= DD.decayProducts()[ix].at(111);
    _h->fill((pi0[0].momentum()+pi0[1].momentum()).mass());
      }
    }


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

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BESIII_2022_I2038523);

}