Rivet analyses

π0 and charged particle spectra at 91 GeV

Experiment: L3 (LEP)

Inspire ID: 314407

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett.B 259 (1991) 199-208

Beams: e+ e-

Beam energies: (45.6, 45.6)GeV

Run details: - e+e- -> hadrons

Measurement of the momentum distribution of the π0 mesons and charged particles at 91.2 GeV in e+e− collisions by the L3 collaboration.

Source code:L3_1991_I314407.cc

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

namespace Rivet {


  /// @brief pi0 and charged particle spectra
  class L3_1991_I314407 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(L3_1991_I314407);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projections
      declare(ChargedFinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      // book histos
      book(_h_pi0_x, 3, 1, 1);
      book(_h_pi0_xi, 4, 1, 1);
      book(_h_charged_x, 5, 1, 1);
      book(_h_charged_xi, 6, 1, 1);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");
      for (const Particle& p : fs.particles()) {
        const double x = 2. * p.momentum().p3().mod() / sqrtS();
        _h_charged_x->fill(x);
        _h_charged_xi->fill(-log(x));
      }
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p : ufs.particles(Cuts::pid == PID::PI0)) {
        const double x = 2. * p.momentum().p3().mod() / sqrtS();
        _h_pi0_x->fill(x);
        _h_pi0_xi->fill(-log(x));
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_h_pi0_x, 1. / sumOfWeights());
      scale(_h_pi0_xi, 1. / sumOfWeights());
      scale(_h_charged_x, 1. / sumOfWeights());
      scale(_h_charged_xi, 1. / sumOfWeights());
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_pi0_x, _h_pi0_xi, _h_charged_x, _h_charged_xi;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(L3_1991_I314407);

}