Rivet analyses

χ_c1 → ηπ⁺π⁻, K⁺K⁻π⁰ and π⁺K⁻K_S⁰

Experiment: CLEO (CESR)

Inspire ID: 732065

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 75 (2007) 032002

Beams: * *

Beam energies: ANY

Run details: - Any process producing chi_c originally e+e-

Measurement of the mass distributions in the decays χ_c1 → ηπ⁺π⁻, K⁺K⁻π⁰ and π⁺K⁻K_S⁰. The data were read from the plots in the paper and may not be corrected for efficiency or background.

Source code:`CLEO_2007_I732065.cc`

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

namespace Rivet {


  /// @brief chi_c1 -> eta pi+pi- and KKpi
  class CLEO_2007_I732065 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2007_I732065);


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

    /// Book histograms and initialise projections before the run
    void init() {
      UnstableParticles ufs = UnstableParticles(Cuts::pid == 20443);
      declare(ufs, "UFS");
      DecayedParticles chi(ufs);
      chi.addStable(PID::PI0);
      chi.addStable(PID::K0S);
      chi.addStable(PID::ETA);
      declare(chi, "chi");
      for (unsigned int ix = 0; ix < 3; ++ix)
        for (unsigned int iy = 0; iy < 3; ++iy) book(_h[ix][iy], ix + 1, 1, iy + 1);
      book(_dalitz[0], "dalitz_1", 50, 0., 12., 50, 0., 9.);
      book(_dalitz[1], "dalitz_2", 50, 0., 10., 50, 0., 10.);
      book(_dalitz[2], "dalitz_3", 50, 0., 10., 50, 0., 10.);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode1 = {{221, 1}, {211, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode2 = {{321, 1}, {-321, 1}, {111, 1}};
      static const map<PdgId, unsigned int>& mode3 = {{-321, 1}, {310, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode4 = {{321, 1}, {310, 1}, {-211, 1}};
      DecayedParticles chi = apply<DecayedParticles>(event, "chi");
      // loop over particles
      for (unsigned int ix = 0; ix < chi.decaying().size(); ++ix) {
        if (chi.modeMatches(ix, 3, mode1)) {
          const Particle& eta = chi.decayProducts()[ix].at(221)[0];
          const Particle& pim = chi.decayProducts()[ix].at(-211)[0];
          const Particle& pip = chi.decayProducts()[ix].at(211)[0];
          double m1 = (pip.momentum() + pim.momentum()).mass2();
          double m2 = (eta.momentum() + pip.momentum()).mass2();
          double m3 = (eta.momentum() + pim.momentum()).mass2();
          _dalitz[0]->fill(m2, m1);
          _h[0][0]->fill(m1);
          _h[0][1]->fill(m2);
          _h[0][2]->fill(m3);
        }
        else if (chi.modeMatches(ix, 3, mode2)) {
          const Particle& pi0 = chi.decayProducts()[ix].at(111)[0];
          const Particle& Km = chi.decayProducts()[ix].at(-321)[0];
          const Particle& Kp = chi.decayProducts()[ix].at(321)[0];
          double m1 = (pi0.momentum() + Km.momentum()).mass2();
          double m2 = (pi0.momentum() + Kp.momentum()).mass2();
          double m3 = (Kp.momentum() + Km.momentum()).mass2();
          _dalitz[1]->fill(m2, m1);
          _h[1][0]->fill(m1);
          _h[1][1]->fill(m2);
          _h[1][2]->fill(m3);
        }
        else {
          int sign = 1;
          if (chi.modeMatches(ix, 3, mode3)) {
            sign = 1;
          }
          else if (chi.modeMatches(ix, 3, mode4)) {
            sign = -1;
          }
          else
            continue;
          const Particle& KS0 = chi.decayProducts()[ix].at(310)[0];
          const Particle& Km = chi.decayProducts()[ix].at(-sign * 321)[0];
          const Particle& pip = chi.decayProducts()[ix].at(sign * 211)[0];
          double m1 = (pip.momentum() + Km.momentum()).mass2();
          double m2 = (pip.momentum() + KS0.momentum()).mass2();
          double m3 = (Km.momentum() + KS0.momentum()).mass2();
          _dalitz[2]->fill(m2, m1);
          _h[2][0]->fill(m1);
          _h[2][1]->fill(m2);
          _h[2][2]->fill(m3);
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 3; ++ix) {
        normalize(_dalitz[ix]);
        for (unsigned int iy = 0; iy < 3; ++iy) normalize(_h[ix][iy]);
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[3][3];
    Histo2DPtr _dalitz[3];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(CLEO_2007_I732065);

}

Rivet analyses

χc1 → ηπ+π−, K+K−π0 and π+K−KS0

Source code:CLEO_2007_I732065.cc

χ_c1 → ηπ⁺π⁻, K⁺K⁻π⁰ and π⁺K⁻K_S⁰

Source code:`CLEO_2007_I732065.cc`