Rivet analyses

title: OPAL_1997_I440721

Event Shapes at 161 GeV

Experiment: OPAL (LEP)

Inspire ID: 440721

Status: VALIDATED

Authors: - Peter Richardson

References: - Z.Phys. C75 (1997) 193-207

Beams: e- e+

Beam energies: (80.5, 80.5)GeV

Run details: - e+e- to hadrons

Event shapes at 161 GeV. Only the evnet shapes are implemented, not the mean values, or the cone jet observables.

Source code:OPAL_1997_I440721.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/ChargedFinalState.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/Hemispheres.hh"

include "Rivet/Projections/ParisiTensor.hh"

include "Rivet/Projections/Sphericity.hh"

include "Rivet/Projections/Thrust.hh"

namespace Rivet {

/// @brief event shapes at 161 class OPAL_1997_I440721 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_1997_I440721);


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

/// Book histograms and initialise projections before the run
void init() {

  // Initialise and register projections
  // Projections
  declare(Beam(), "Beams");
  const FinalState fs;
  declare(fs, "FS");
  const ChargedFinalState cfs;
  declare(cfs, "CFS");
  declare(FastJets(fs, JetAlg::DURHAM, 0.7), "DurhamJets");
  declare(Sphericity(fs), "Sphericity");
  declare(ParisiTensor(fs), "Parisi");
  const Thrust thrust(fs);
  declare(thrust, "Thrust");
  declare(Hemispheres(thrust), "Hemispheres");

  // Book histograms
  book(_h_mult_avrg, 2, 1, 1);
  book(_h_thrust, 3, 1, 1);
  book(_h_major, 4, 1, 1);
  book(_h_minor, 5, 1, 1);
  book(_h_aplanarity, 8, 1, 1);
  book(_h_oblateness, 6, 1, 1);
  book(_h_C, 9, 1, 1);
  book(_h_rhoH, 10, 1, 1);
  book(_h_sphericity, 7, 1, 1);
  book(_h_totalB, 11, 1, 1);
  book(_h_wideB, 12, 1, 1);
  book(_h_y23, 20, 1, 1);
  book(_h_pTin, 21, 1, 1);
  book(_h_pTout, 22, 1, 1);
  book(_h_y, 23, 1, 1);
  book(_h_x, 24, 1, 1);
  book(_h_xi, 25, 1, 1);
  book(_h_mult, 26, 1, 1);
  book(_sumW, "/TMP/sumW");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
  const FinalState& cfs = apply<FinalState>(event, "CFS");
  if (cfs.size() < 2) vetoEvent;
  _sumW->fill();

  // 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;

  // Thrust related
  const Thrust& thrust = apply<Thrust>(event, "Thrust");
  _h_thrust->fill(thrust.thrust());
  _h_major->fill(thrust.thrustMajor());
  _h_minor->fill(thrust.thrustMinor());
  _h_oblateness->fill(thrust.oblateness());

  // Sphericity related
  const Sphericity& sphericity = apply<Sphericity>(event, "Sphericity");
  _h_sphericity->fill(sphericity.sphericity());
  _h_aplanarity->fill(sphericity.aplanarity());

  // C parameter
  const ParisiTensor& parisi = apply<ParisiTensor>(event, "Parisi");
  _h_C->fill(parisi.C());

  // Hemispheres
  const Hemispheres& hemi = apply<Hemispheres>(event, "Hemispheres");

  _h_rhoH->fill(hemi.scaledMhigh());
  _h_wideB->fill(hemi.Bmax());
  _h_totalB->fill(hemi.Bsum());

  // Jets
  const FastJets& durjet = apply<FastJets>(event, "DurhamJets");
  const double y23 = durjet.clusterSeq()->exclusive_ymerge_max(2);
  _h_y23->fill(y23);

  // charged particles
  _h_mult->fill(cfs.particles().size());
  _h_mult_avrg->fill(161, cfs.particles().size());
  for (const Particle& p : cfs.particles()) {
    const Vector3 mom3 = p.p3();
    const double energy = p.E();
    const double pTinT = dot(mom3, thrust.thrustMajorAxis());
    const double pToutT = dot(mom3, thrust.thrustMinorAxis());
    _h_pTin->fill(fabs(pTinT / GeV));
    _h_pTout->fill(fabs(pToutT / GeV));
    const double momT = dot(thrust.thrustAxis(), mom3);
    const double rapidityT = 0.5 * std::log((energy + momT) / (energy - momT));
    _h_y->fill(fabs(rapidityT));
    const double mom = mom3.mod();
    const double scaledMom = mom / meanBeamMom;
    const double logInvScaledMom = -std::log(scaledMom);
    _h_xi->fill(logInvScaledMom);
    _h_x->fill(scaledMom);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_thrust, 1. / *_sumW);
  scale(_h_major, 1. / *_sumW);
  scale(_h_minor, 1. / *_sumW);
  scale(_h_aplanarity, 1. / *_sumW);
  scale(_h_oblateness, 1. / *_sumW);
  scale(_h_C, 1. / *_sumW);
  scale(_h_rhoH, 1. / *_sumW);
  scale(_h_sphericity, 1. / *_sumW);
  scale(_h_totalB, 1. / *_sumW);
  scale(_h_wideB, 1. / *_sumW);
  scale(_h_y23, 1. / *_sumW);
  scale(_h_mult, 100. / *_sumW);
  scale(_h_pTin, 1. / *_sumW);
  scale(_h_pTout, 1. / *_sumW);
  scale(_h_y, 1. / *_sumW);
  scale(_h_x, 1. / *_sumW);
  scale(_h_xi, 1. / *_sumW);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_thrust, _h_major, _h_minor, _h_aplanarity, _h_oblateness, _h_C, _h_rhoH, _h_sphericity;
Histo1DPtr _h_totalB, _h_wideB, _h_y23, _h_pTin, _h_pTout, _h_y, _h_x, _h_xi;
BinnedHistoPtr<int> _h_mult;
BinnedProfilePtr<int> _h_mult_avrg;
CounterPtr _sumW;
/// @}

};

RIVET_DECLARE_PLUGIN(OPAL_1997_I440721);

} ```