Rivet analyses

Hadronic Mass distribution in τ⁻ → 2π⁻π⁺3π⁰ν_τ and 3π⁻2π⁺π⁰ν_τ

Experiment: CLEO (CESR)

Inspire ID: 535016

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 86 (2001) 4467-4471

Beams: * *

Beam energies: ANY

Run details: - Any process producing tau leptons, originally e+e-

Measurement of the hadronic mass distribution in n τ⁻ → 2π⁻π⁺3π⁰ν_τ and 3π⁻2π⁺π⁰ν_τ. The data were read from the plots in the paper and are not corrected, although the backgrounds given in the paper have been subtracted. The plots should therefore only be used for qualitative comparisons however the data is useful as there are not corrected distributions for this decay mode.

Source code:`CLEO_2001_I535016.cc`

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

namespace Rivet {


  /// @brief  tau -> 6 pion final states
  class CLEO_2001_I535016 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2001_I535016);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid==15);
      declare(ufs, "UFS");
      DecayedParticles TAU(ufs);
      TAU.addStable(310);
      TAU.addStable(111);
      declare(TAU, "TAU");
      // histogram
      for (unsigned int ix=0; ix<2; ++ix) {
        book(_h[ix],1,1,1+ix);
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      DecayedParticles TAU = apply<DecayedParticles>(event, "TAU");
      // loop over particles
      for (unsigned int ix=0; ix<TAU.decaying().size(); ++ix) {
        int sign = TAU.decaying()[ix].pid()>0 ? 1 : -1;
        int imode=-1;
        if (TAU.modeMatches(ix,7,mode1  ) ||
            TAU.modeMatches(ix,7,mode1CC)) imode = 0;
        else if (TAU.modeMatches(ix,7,mode2) ||
                 TAU.modeMatches(ix,7,mode2CC)) imode = 1;
        else continue;
        const Particles& pip = TAU.decayProducts()[ix].at( 211*sign);
        const Particles& pim = TAU.decayProducts()[ix].at(-211*sign);
        const Particles& pi0 = TAU.decayProducts()[ix].at( 111);
        FourMomentum ptotal;
        for (unsigned int ix=0;ix<pim.size();++ix) ptotal +=pim[ix].momentum();
        for (unsigned int ix=0;ix<pip.size();++ix) ptotal +=pip[ix].momentum();
        for (unsigned int ix=0;ix<pi0.size();++ix) ptotal +=pi0[ix].momentum();
        _h[imode]->fill(ptotal.mass());
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      normalize(_h, 1.0,false);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[2];
    const map<PdgId,unsigned int> mode1   = { {-211,2}, { 211,1},{111,3},{ 16,1}};
    const map<PdgId,unsigned int> mode1CC = { { 211,2}, {-211,1},{111,3},{-16,1}};
    const map<PdgId,unsigned int> mode2   = { {-211,3}, { 211,2},{111,1},{ 16,1}};
    const map<PdgId,unsigned int> mode2CC = { { 211,3}, {-211,2},{111,1},{-16,1}};
    /// @}


  };


  RIVET_DECLARE_PLUGIN(CLEO_2001_I535016);

}

Rivet analyses

Hadronic Mass distribution in τ− → 2π−π+3π0ντ and 3π−2π+π0ντ

Source code:CLEO_2001_I535016.cc

Hadronic Mass distribution in τ⁻ → 2π⁻π⁺3π⁰ν_τ and 3π⁻2π⁺π⁰ν_τ

Source code:`CLEO_2001_I535016.cc`