Rivet analyses

title: BELLE_2019_I1718551

Cross sections for $\pi^\pm$, $K^\pm$ and $p\bar{p}$ as functions of $z$ and $p_\perp$ at $E_{\text{cms}}=10.58$ GeV

Experiment: BELLE (KEKB)

Inspire ID: 1718551

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D92 (2015) no.9, 092007

Beams: e+ e-

Beam energies: (5.3, 5.3)GeV

Run details: - e+e- to hadrons at 10.58 continuum events only

Cross sections for $\pi^\pm$, $K^\pm$ and $p\bar{p}$ as functions of $z$ and $p_\perp$ at $E_{\text{cms}}=10.58$ GeV

Source code:BELLE_2019_I1718551.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/Thrust.hh"

namespace Rivet {

/// @brief pi, kaon and proton spectra at 10.58 GeV class BELLE_2019_I1718551 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2019_I1718551);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  const FinalState fs;
  declare(fs, "FS");
  declare(Thrust(fs), "Thrust");
  declare(Beam(), "Beams");

  for (size_t ix = 0; ix < 6; ++ix) {

    if (ix == 1 || ix == 2) {
      book(_proton[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85});
    }
    else if (ix) {
      book(_proton[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85,
            0.90});
    }
    else {
      book(_proton[ix], {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.70});
    }

    if (ix) {
      book(_pion[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9,
            0.95, 1.0});
      book(_kaon[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9,
            0.95, 1.0});
    }
    else {
      book(_pion[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85,
            0.90});
      book(_kaon[ix],
           {0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85});
    }
    for (size_t iy = 0; iy < _pion[ix]->numBins(); ++iy) {
      book(_pion[ix]->bin(iy + 1), 1, ix + 1, iy + 1);
      book(_kaon[ix]->bin(iy + 1), 2, ix + 1, iy + 1);
    }
    for (size_t iy = 0; iy < _proton[ix]->numBins(); ++iy) {
      book(_proton[ix]->bin(iy + 1), 3, ix + 1, iy + 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;
  // get the thrust
  const vector<double> tbins{0.7, 0.8, 0.85, 0.9, 0.95, 1.0};
  const Thrust& thrust = apply<Thrust>(event, "Thrust");
  // find the thrust bin
  unsigned int ithrust = 0;
  for (; ithrust < tbins.size(); ++ithrust) {
    if (thrust.thrust() <= tbins[ithrust]) break;
  }
  Vector3 a1 = thrust.thrustMajorAxis();
  Vector3 a2 = thrust.thrustMinorAxis();
  // loop over the charged hadrons
  const FinalState& fs = apply<FinalState>(event, "FS");
  for (const Particle& charged :
       fs.particles(Cuts::abspid == 211 or Cuts::abspid == 321 or Cuts::abspid == 2212)) {
    double xE = charged.momentum().t() / meanBeamMom;
    double pT = sqrt(sqr(a1.dot(charged.momentum().p3())) + sqr(a2.dot(charged.momentum().p3())));
    if (charged.abspid() == 211) {
      _pion[ithrust]->fill(xE, pT);
    }
    else if (charged.abspid() == 321) {
      _kaon[ithrust]->fill(xE, pT);
    }
    else if (charged.abspid() == 2212) {
      _proton[ithrust]->fill(xE, pT);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // scale factor including bin width in x_E
  const double fact = crossSection() / femtobarn / sumOfWeights() / 0.05;
  scale(_pion, fact);
  scale(_kaon, fact);
  scale(_proton, fact);
}

/// @}


/// @name Histograms
/// @{
Histo1DGroupPtr _pion[6], _kaon[6], _proton[6];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2019_I1718551);

} ```