Rivet analyses

Spectra of ρ0 and K*± in e+e− collisions at 35 GeV

Experiment: JADE (PETRA)

Inspire ID: 203145

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B145 (1984) 441-447, 1984

Beams: e+ e-

Beam energies: (17.5, 17.5)GeV

Run details: - e+ e- to hadrons

Measurement of the ρ0 and K*± spectra in e+e− collisions for centre-of-mass energy 35 GeV by the JADE experiment at Petra.

Source code:JADE_1984_I203145.cc

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

namespace Rivet {


  /// @brief rho0 and K*+/- spectra at 35 GeV
  class JADE_1984_I203145 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(JADE_1984_I203145);


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

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

      // Initialise and register projections
      declare(Beam(), "Beams");
      declare(UnstableParticles(), "UFS");

      // Book histograms
      book(_h_rho, 2, 1, 1);
      book(_h_kstar, 3, 1, 1);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {

      // 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);

      for (const Particle& p :
           apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid == 323 or Cuts::pid == 113)) {
        double xE = p.E() / meanBeamMom;
        double modp = p.p3().mod();
        double beta = modp / p.E();
        if (p.pid() == 113) {
          _h_rho->fill(xE, 1. / beta);
        }
        else {
          _h_kstar->fill(xE, 1. / beta);
        }
      }
    }


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

      scale(_h_rho, sqr(sqrtS()) * crossSection() / nanobarn / sumOfWeights());
      scale(_h_kstar, sqr(sqrtS()) * crossSection() / nanobarn / sumOfWeights());
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_rho, _h_kstar;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(JADE_1984_I203145);


}