Rivet analyses

title: CLEO_2009_I822856

Pion mass distribution in $D^+_s\to \omega\pi^+\pi^0$

Experiment: CLEO (CESR)

Inspire ID: 822856

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 80 (2009) 051102

Beams: * *

Beam energies: ANY

Run details: - Any process producing D_s+

Measurement of the pion mass distribution in $D^+_s\to \omega\pi^+\pi^0$. The data were read from the plots in the paper. Resolution/acceptance effects have been not unfolded. Given the agreement with the model in the paper this analysis should only be used for qualitative studies.

Source code:CLEO_2009_I822856.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief D_s+ -> omega pi+ pi0 class CLEO_2009_I822856 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2009_I822856);


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

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


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode = {{211, 1}, {111, 1}, {223, 1}};
  static const map<PdgId, unsigned int>& modeCC = {{-211, 1}, {111, 1}, {223, 1}};
  DecayedParticles DS = apply<DecayedParticles>(event, "DS");
  // loop over particles
  for (unsigned int ix = 0; ix < DS.decaying().size(); ++ix) {
    int sign = 1;
    if (DS.decaying()[ix].pid() > 0 && DS.modeMatches(ix, 3, mode)) {
      sign = 1;
    }
    else if (DS.decaying()[ix].pid() < 0 && DS.modeMatches(ix, 3, modeCC)) {
      sign = -1;
    }
    else
      continue;
    const Particles& pi0 = DS.decayProducts()[ix].at(111);
    const Particles& pip = DS.decayProducts()[ix].at(sign * 211);
    _h_pipi->fill((pi0[0].momentum() + pip[0].momentum()).mass());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  normalize(_h_pipi, 1., false);
}

/// @}


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

};

RIVET_DECLARE_PLUGIN(CLEO_2009_I822856);

} ```