Rivet analyses

title: MARKII_1988_I246184

Event shapes at 29 GeV

Experiment: MARKII (PEP)

Inspire ID: 246184

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.D 37 (1988) 1, 1988

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: - e+ e- to hadrons

Event shapes measured by the MARKII collaboration at 29 GeV.

Source code:MARKII_1988_I246184.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/ChargedFinalState.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/Hemispheres.hh"

include "Rivet/Projections/Sphericity.hh"

include "Rivet/Projections/Thrust.hh"

namespace Rivet {

/// @brief Event shapes at 29 GeV class MARKII_1988_I246184 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MARKII_1988_I246184);


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

/// Book histograms and initialise projections before the run
void init() {
  const FinalState fs;
  declare(fs, "FS");
  const ChargedFinalState cfs;
  declare(cfs, "CFS");
  Sphericity sphere(fs);
  declare(sphere, "Sphericity");
  declare(Thrust(fs), "Thrust");
  declare(Hemispheres(sphere), "Hemispheres");
  // histograms
  unsigned int ioff = 18;
  for (unsigned int ix = 0; ix < 3; ++ix) {
    book(_histAplanarity[ix], 1 + ioff * ix, 1, 1);
    book(_histQx[ix], 2 + ioff * ix, 1, 1);
    book(_histQ2Q1[ix], 3 + ioff * ix, 1, 1);
    book(_histSphericity[ix], 4 + ioff * ix, 1, 1);
    book(_histThrust[ix], 5 + ioff * ix, 1, 1);
    book(_histMinor[ix], 6 + ioff * ix, 1, 1);
    book(_histOblateness[ix], 7 + ioff * ix, 1, 1);
    book(_histMJetBroad[ix], 8 + ioff * ix, 1, 1);
    book(_histMJetSlim[ix], 9 + ioff * ix, 1, 1);
    book(_histMJetDiff[ix], 10 + ioff * ix, 1, 1);
    book(_histScaledMom[ix], 15 + ioff * ix, 1, 1);
    book(_histPt2S[ix], 11 + ioff * ix, 1, 1);
    book(_histPtS[ix], 12 + ioff * ix, 1, 1);
    book(_histPtSIn[ix], 14 + ioff * ix, 1, 1);
    book(_histPtSOut[ix], 13 + ioff * ix, 1, 1);
    book(_histRapidityS[ix], 16 + ioff * ix, 1, 1);
    book(_histTheta[ix], 17 + ioff * ix, 1, 1);
    book(_histETheta[ix], 18 + ioff * ix, 1, 1);
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // Sphericity related
  const Sphericity& sphericity = apply<Sphericity>(event, "Sphericity");
  for (unsigned int ix = 0; ix < 3; ++ix) {
    _histSphericity[ix]->fill(sphericity.sphericity());
    _histAplanarity[ix]->fill(sphericity.aplanarity());
    _histQx[ix]->fill((sphericity.lambda1() - sphericity.lambda2()) / sqrt(3.));
    _histQ2Q1[ix]->fill(sphericity.lambda2() - sphericity.lambda3());
  }
  // thrust related
  const Thrust& thrust = apply<Thrust>(event, "Thrust");
  for (unsigned int ix = 0; ix < 3; ++ix) {
    _histThrust[ix]->fill(thrust.thrust());
    _histMinor[ix]->fill(thrust.thrustMinor());
    _histOblateness[ix]->fill(thrust.oblateness());
  }
  // hemisphere related
  const Hemispheres& hemi = apply<Hemispheres>(event, "Hemispheres");
  double mWide = hemi.scaledM2high(), mNarrow = hemi.scaledM2low();
  if (!hemi.massMatchesBroadening()) swap(mWide, mNarrow);
  for (unsigned int ix = 0; ix < 3; ++ix) {
    _histMJetBroad[ix]->fill(mWide);
    _histMJetSlim[ix]->fill(mNarrow);
    _histMJetDiff[ix]->fill(hemi.scaledM2diff());
  }
  // dists w.r.t sphericity axis
  const FinalState& cfs = apply<FinalState>(event, "CFS");
  for (const Particle& p : cfs.particles()) {
    // Get momentum and energy of each particle.
    const Vector3 mom3 = p.p3();
    const double energy = p.E();
    // Scaled momenta.
    const double mom = mom3.mod();
    const double scaledMom = 2. * mom / sqrtS();
    // Get momenta components w.r.t. thrust and sphericity.
    const double pTinS = dot(mom3, sphericity.sphericityMajorAxis());
    const double pToutS = dot(mom3, sphericity.sphericityMinorAxis());
    double pT2 = sqr(pTinS) + sqr(pToutS);
    double pT = sqrt(pT2);
    const double momS = dot(sphericity.sphericityAxis(), mom3);
    const double rapidityS = 0.5 * std::log((energy + momS) / (energy - momS));
    // angle
    double theta = sphericity.sphericityAxis().angle(mom3) / M_PI * 180.;
    if (theta > 90.) theta = 180. - theta;
    // fill histos
    for (unsigned int ix = 0; ix < 3; ++ix) {
      _histScaledMom[ix]->fill(scaledMom);
      _histPt2S[ix]->fill(fabs(pT2 / GeV));
      _histPtS[ix]->fill(fabs(pT / GeV));
      _histPtSIn[ix]->fill(fabs(pTinS / GeV));
      _histPtSOut[ix]->fill(fabs(pToutS / GeV));
      _histRapidityS[ix]->fill(fabs(rapidityS));
      _histTheta[ix]->fill(theta);
    }
  }
  // energy flow includes neutral w.r.t sphericity axis
  const FinalState& fs = apply<FinalState>(event, "FS");
  for (const Particle& p : fs.particles()) {
    // Get momentum and energy of each particle.
    const Vector3 mom3 = p.p3();
    const double energy = p.E();
    // angle
    double theta = sphericity.sphericityAxis().angle(mom3) / M_PI * 180.;
    if (theta > 90.) theta = 180. - theta;
    // fill histos
    for (unsigned int ix = 0; ix < 3; ++ix) {
      _histETheta[ix]->fill(theta, energy);
    }
  }
}

/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 3; ++ix) {
    scale(_histAplanarity[ix], 1. / sumOfWeights());
    scale(_histQx[ix], 1. / sumOfWeights());
    scale(_histQ2Q1[ix], 1. / sumOfWeights());
    scale(_histSphericity[ix], 1. / sumOfWeights());
    scale(_histThrust[ix], 1. / sumOfWeights());
    scale(_histMinor[ix], 1. / sumOfWeights());
    scale(_histOblateness[ix], 1. / sumOfWeights());
    scale(_histMJetBroad[ix], 1. / sumOfWeights());
    scale(_histMJetSlim[ix], 1. / sumOfWeights());
    scale(_histMJetDiff[ix], 1. / sumOfWeights());
    scale(_histScaledMom[ix], 1. / sumOfWeights());
    scale(_histPt2S[ix], 1. / sumOfWeights());
    scale(_histPtS[ix], 1. / sumOfWeights());
    scale(_histPtSIn[ix], 1. / sumOfWeights());
    scale(_histPtSOut[ix], 1. / sumOfWeights());
    scale(_histRapidityS[ix], 1. / sumOfWeights());
    scale(_histTheta[ix], 1. / sumOfWeights());
    scale(_histETheta[ix], 1. / sumOfWeights());
  }
}

///@}


/// @name Histograms
///@{
Histo1DPtr _histAplanarity[3], _histQx[3], _histQ2Q1[3], _histSphericity[3];
Histo1DPtr _histThrust[3], _histMinor[3], _histOblateness[3];
Histo1DPtr _histMJetBroad[3], _histMJetSlim[3], _histMJetDiff[3];
Histo1DPtr _histScaledMom[3], _histPt2S[3], _histPtS[3], _histPtSIn[3], _histPtSOut[3], _histRapidityS[3];
Histo1DPtr _histTheta[3], _histETheta[3];
///@}

};

RIVET_DECLARE_PLUGIN(MARKII_1988_I246184);

} ```