Rivet analyses

Hadronic mass spectra in four hadron τ− decays with K±

Experiment: CLEOIII (CESR)

Inspire ID: 675005

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 94 (2005) 241802

Beams: * *

Beam energies: ANY

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

Measurement of the hadronic mass spectrum in τ− → K−π+π−π0ντ (excluding ω and K−ωντ) and τ− → K−K+π−π0ντ decays. The background subtracted, efficiency corrected data were read from Figure 2 in the paper.

Source code:CLEOIII_2005_I675005.cc

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

namespace Rivet {


  /// @brief Hadronic mass spectra in four hadron tau- decays with K+/-
  class CLEOIII_2005_I675005 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOIII_2005_I675005);


    /// @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(223);
      TAU.addStable(111);
      declare(TAU, "TAU");
      // histos
      for (unsigned int ix = 0; ix < 3; ++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 = 1, imode = 0;
        if (TAU.decaying()[ix].pid() > 0 && TAU.modeMatches(ix, 5, mode1)) {
          sign = 1;
          imode = 0;
        }
        else if (TAU.decaying()[ix].pid() < 0 && TAU.modeMatches(ix, 5, mode1CC)) {
          sign = -1;
          imode = 0;
        }
        else if (TAU.decaying()[ix].pid() > 0 && TAU.modeMatches(ix, 3, mode2)) {
          sign = 1;
          imode = 1;
        }
        else if (TAU.decaying()[ix].pid() < 0 && TAU.modeMatches(ix, 3, mode2CC)) {
          sign = -1;
          imode = 1;
        }
        else if (TAU.decaying()[ix].pid() > 0 && TAU.modeMatches(ix, 5, mode3)) {
          sign = 1;
          imode = 2;
        }
        else if (TAU.decaying()[ix].pid() < 0 && TAU.modeMatches(ix, 5, mode3CC)) {
          sign = -1;
          imode = 2;
        }
        else {
          continue;
        }
        const Particle& nu = TAU.decayProducts()[ix].at(16 * sign)[0];
        const double mass = (TAU.decaying()[ix].mom() - nu.mom()).mass();
        _h[imode]->fill(mass);
      }
    }


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

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[3];
    const map<PdgId, unsigned int> mode1 = {{-321, 1}, {211, 1}, {-211, 1}, {111, 1}, {16, 1}};
    const map<PdgId, unsigned int> mode1CC = {{321, 1}, {211, 1}, {-211, 1}, {111, 1}, {-16, 1}};
    const map<PdgId, unsigned int> mode2 = {{-321, 1}, {223, 1}, {16, 1}};
    const map<PdgId, unsigned int> mode2CC = {{321, 1}, {223, 1}, {-16, 1}};
    const map<PdgId, unsigned int> mode3 = {{321, 1}, {-321, 1}, {-211, 1}, {111, 1}, {16, 1}};
    const map<PdgId, unsigned int> mode3CC = {{321, 1}, {-321, 1}, {211, 1}, {111, 1}, {-16, 1}};
    /// @}
  };


  RIVET_DECLARE_PLUGIN(CLEOIII_2005_I675005);

}