Rivet analyses

title: TPC_1984_I200105

$\phi$ spectrum at 29 GeV

Experiment: TPC (PEP)

Inspire ID: 200105

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 52 (1984) 2201, 1984

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: - e+e- to hadrons at 29 GeV

Measurement of the $\phi$ spectra at 29 GeV by the TPC experiment.

Source code:TPC_1984_I200105.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/Thrust.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Add a short analysis description here class TPC_1984_I200105 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(TPC_1984_I200105);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(Beam(), "Beams");
  const FinalState cfs(Cuts::charge != 0);
  declare(cfs, "FS");
  const Thrust thrust(cfs);
  declare(thrust, "Thrust");
  declare(UnstableParticles(), "UFS");

  // Book histograms
  book(_h_x, 1, 1, 1);
  book(_h_pt, 3, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // require 5 charged particles
  const FinalState& fs = apply<FinalState>(event, "FS");
  if (fs.size() < 3) vetoEvent;
  // Get beams and average beam momentum
  const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
  const double meanBeamMom = (beams.first.p3().mod() + beams.second.p3().mod()) / 2.0;
  MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
  // calc thrust
  const Thrust& thrust = apply<Thrust>(event, "Thrust");
  Vector3 axis = thrust.thrustAxis();
  // Final state of unstable particles to get particle spectra
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p : ufs.particles(Cuts::pid == 333)) {
    double xE = p.E() / meanBeamMom;
    double pT2 = p.p3().mod2() - sqr(axis.dot(p.p3()));
    _h_x->fill(xE);
    _h_pt->fill(pT2);
  }
}


/// Normalise histograms etc., after the run
void finalize() {

  scale(_h_x, 1. / sumOfWeights());
  scale(_h_pt, 1. / sumOfWeights());
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_x, _h_pt;
/// @}

};

RIVET_DECLARE_PLUGIN(TPC_1984_I200105);

} ```