Rivet analyses

Spectrum for D*+ production in e+e− collisions at ECMS = 36.2

Experiment: TASSO (Petra)

Inspire ID: 278856

Status: VALIDATED

Authors: - Peter Richardson

References: - Z.Phys. C44 (1989) 365, 1989

Beams: e+ e-

Beam energies: (17.2, 17.2)GeV

Run details: - e+ e- to hadrons

Measurement of the D*+ momentum spectrum in e+e− collisions for a mean centre-of-mass energy of 36.2 GeV by the TASSO experiment at Petra. Only the spectra are implemented.

Source code:TASSO_1989_I278856.cc

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

namespace Rivet {


  /// @brief D* production at 36.2 GeV
  class TASSO_1989_I278856 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(TASSO_1989_I278856);


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

    /// Book histograms and initialise projections before the run
    void init() {
      declare(Beam(), "Beams");
      declare(UnstableParticles(), "UFS");

      // Book histograms
      book(_h_x_A1, 1, 1, 1);
      book(_h_x_A2, 1, 1, 2);
      book(_h_x_B1, 2, 1, 1);
      book(_h_x_B2, 2, 1, 2);
    }


    /// 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);
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p : ufs.particles(Cuts::abspid==413)) {
    double modp = p.p3().mod();
    double xE = p.E()/meanBeamMom;
    double beta = modp/p.E();
    _h_x_A1->fill(xE);
    _h_x_A2->fill(xE,1./beta);
    _h_x_B1->fill(xE);
    _h_x_B2->fill(xE,1./beta);
      }
    }


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

      scale(_h_x_A1, crossSection()/picobarn/sumOfWeights());
      scale(_h_x_A2, sqr(sqrtS())*crossSection()/nanobarn/sumOfWeights());
      scale(_h_x_B1, crossSection()/picobarn/sumOfWeights());
      scale(_h_x_B2, sqr(sqrtS())*crossSection()/nanobarn/sumOfWeights());
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_x_A1, _h_x_A2, _h_x_B1, _h_x_B2;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(TASSO_1989_I278856);


}