Rivet analyses

Measurement of the Λc+ spectrum at 10.55 GeV

Experiment: CLEO (CESR)

Inspire ID: 298611

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D43 (1991) 3599-3610, 1991

Beams: e+ e-

Beam energies: (5.3, 5.3)GeV

Run details: - e+e- to hadrons

Measurement for the scaled momentum spectrum for Λc+ baryons in the continuum by CLEO.

Source code:CLEO_1990_I298611.cc

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

namespace Rivet {


  /// @brief Lambda_c spectra
  class CLEO_1990_I298611 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_1990_I298611);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projections
      declare(Beam(), "Beams");
      declare(UnstableParticles(), "UFS");
      // histograms
      for (unsigned int ix = 0; ix < 6; ++ix) {
        _h_x.push_back(Histo1DPtr());
        book(_h_x[ix], ix + 1, 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 Emax = (beams.first.p3().mod() + beams.second.p3().mod()) / 2.0;
      const double Pmax = sqrt(sqr(Emax) - sqr(2.28646));
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p : ufs.particles(Cuts::abspid == 4122)) {
        double xp = p.momentum().p3().mod() / Pmax;
        for (unsigned int ix = 0; ix < 6; ++ix) _h_x[ix]->fill(xp);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // branching ratios for the different modes used in the measurements
      double br[6] = {0.0623, 2. * 0.0158, 2. * 0.0159, 0.0129, 0.0361, 0.0062};
      for (unsigned int ix = 0; ix < 6; ++ix)
        scale(_h_x[ix], crossSection() * br[ix] / picobarn / sumOfWeights());
    }

    /// @}


    /// @name Histograms
    /// @{
    vector<Histo1DPtr> _h_x;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(CLEO_1990_I298611);

}