Rivet analyses

title: TASSO_1989_I278856

Spectrum for $D^{*+}$ production in $e^+e^-$ collisions at $E_{\text{CMS}}=36.2$

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++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/UnstableParticles.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);

} ```