Rivet analyses

title: JADE_1981_I166363

Spectra for anti-protons and $\bar{\Lambda}^0$ at 34 GeV

Experiment: JADE (Petra)

Inspire ID: 166363

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. 104B (1981) 325-329

Beams: e+ e-

Beam energies: (17.0, 17.0)GeV

Run details: - e+ e- to hadrons

Measurement of the anti-proton and $\bar{\Lambda}^0$ momentum spectrum in $e^+e^-$ collisions for a centre-of-mass energy of 34 GeV by the JADE experiment at Petra. Useful as not summed over particle and antiparticle, only the antibaryons are included.

Source code:JADE_1981_I166363.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief pbar and lambdabar at 34 GeV class JADE_1981_I166363 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(JADE_1981_I166363);


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

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

  // Initialise and register projections
  declare(FinalState(), "FS");
  declare(UnstableParticles(), "UFS");

  // Book histograms
  book(_h_pbar, 1, 1, 1);
  book(_h_lambdabar, 2, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // at least 5 charged FS particles
  const FinalState& fs = apply<FinalState>(event, "FS");
  const size_t numParticles = fs.particles().size();

  if (numParticles < 3) {
    MSG_DEBUG("Failed leptonic event cut");
    vetoEvent;
  }
  MSG_DEBUG("Passed leptonic event cut");

  for (const Particle& p :
       apply<UnstableParticles>(event, "UFS").particles(Cuts::pid == -2212 or Cuts::pid == -3122)) {
    if (p.pid() == -2212)
      _h_pbar->fill(p.p3().mod());
    else
      _h_lambdabar->fill(p.p3().mod());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_pbar, crossSection() / nanobarn / sumOfWeights());
  scale(_h_lambdabar, crossSection() / nanobarn / sumOfWeights());
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_pbar, _h_lambdabar;
/// @}

};

RIVET_DECLARE_PLUGIN(JADE_1981_I166363);

} ```