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/DecayedParticles.hh"
#include "Rivet/Projections/UnstableParticles.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);

}