Rivet analyses

title: CLEO_2000_I525698

Mass distributions in $\tau^-\to K^-\pi^+\pi^-\nu_\tau$

Experiment: CLEO (CESR)

Inspire ID: 525698

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 62 (2000) 072006

Beams: * *

Beam energies: ANY

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

Measurement of mass distributions in $\tau^-\to K^-\pi^+\pi^-\nu_\tau$. The background subtracted, corrected data were read from figure 2 in the paper.

Source code:CLEO_2000_I525698.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief tau -> K- pi+ pi- nu_tau class CLEO_2000_I525698 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2000_I525698);


/// @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 < 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 = TAU.decaying()[ix].pid() > 0 ? 1 : -1;
    if (!(TAU.modeMatches(ix, 4, mode) || TAU.modeMatches(ix, 4, modeCC))) continue;
    const Particle& pip = TAU.decayProducts()[ix].at(211 * sign)[0];
    const Particle& pim = TAU.decayProducts()[ix].at(-211 * sign)[0];
    const Particle& Km = TAU.decayProducts()[ix].at(-321 * sign)[0];
    _h[0]->fill((Km.mom() + pip.mom() + pim.mom()).mass());
    _h[1]->fill((Km.mom() + pip.mom()).mass());
    _h[2]->fill((pip.mom() + pim.mom()).mass());
  }
}


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

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[3];
const map<PdgId, unsigned int> mode = {{-321, 1}, {211, 1}, {-211, 1}, {16, 1}};
const map<PdgId, unsigned int> modeCC = {{321, 1}, {-211, 1}, {211, 1}, {-16, 1}};
/// @}

};

RIVET_DECLARE_PLUGIN(CLEO_2000_I525698);

} ```