Rivet analyses

title: HRS_1989_I276948

$\rho^0$, $K^{0}$ and $K^{\pm}$ spectra at 29 GeV

Experiment: HRS (PEP)

Inspire ID: 276948

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.D 40 (1989) 706, 1989

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: none listed

Measurement of the $\rho^0$, $K^{0}$ and $K^{\pm}$ spectra at 29 GeV by the HRS experiment.

Source code:HRS_1989_I276948.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief rho0, K=, K0 spectra at 29 GeV class HRS_1989_I276948 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1989_I276948);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(UnstableParticles(), "UFS");
  book(_h["rho"], 1, 1, 1);
  book(_h["Kstar0"], 2, 1, 1);
  book(_h["Kstarp"], 2, 1, 2);
  book(_h_sig_rho, 3, 1, 1);
  book(_h_sig_Kstar0, 4, 1, 1);
  book(_h_mult_rho, 3, 1, 3);
  book(_h_mult_Kstar0, 4, 1, 3);
  _axes["rho"] = YODA::Axis<double>({0.0725, 0.0925, 0.114,  0.136,  0.159, 0.183,  0.207,  0.231,
                                     0.2555, 0.28,   0.3045, 0.3295, 0.354, 0.3785, 0.4035, 0.4285,
                                     0.4595, 0.5155, 0.6025, 0.702,  0.802, 0.902});
  _axes["Kstar0"] = YODA::Axis<double>(
      {0.077, 0.119, 0.163, 0.2095, 0.2575, 0.3065, 0.3555, 0.405, 0.455, 0.5, 0.6, 0.7, 1.0});
  _axes["Kstarp"] = _axes["Kstar0"];
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  if (_edges.empty()) {
    for (const auto& item : _h) {
      _edges[item.first] = item.second->xEdges();
    }
  }
  UnstableParticles ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p :
       ufs.particles(Cuts::abspid == 113 || Cuts::abspid == 323 || Cuts::abspid == 313)) {
    Vector3 mom3 = p.p3();
    const double energy = p.E();
    double modp = mom3.mod();
    double beta = modp / energy;
    double xE = 2. * modp / sqrtS();
    if (p.pid() == 113) {
      discfill("rho", xE, 1. / beta);
      _h_sig_rho->fill(29);
      _h_mult_rho->fill(29);
    }
    else if (p.pid() == 313) {
      discfill("Kstar0", xE, 1. / beta);
      _h_sig_Kstar0->fill(29);
      _h_mult_Kstar0->fill(29);
    }
    else {
      discfill("Kstarp", xE, 1. / beta);
    }
  }
}

void discfill(const string& name, const double val, const double weight) {
  string edge = "OTHER";
  const size_t idx = _axes[name].index(val);
  if (idx && idx <= _edges[name].size()) edge = _edges[name][idx - 1];
  _h[name]->fill(edge, weight);
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h, sqr(sqrtS()) * crossSection() / microbarn / sumOfWeights());
  scale({_h_sig_rho, _h_sig_Kstar0}, crossSection() / picobarn / sumOfWeights());
  scale({_h_mult_rho, _h_mult_Kstar0}, 1. / sumOfWeights());
  for (auto& hist : _h) {
    for (auto& b : hist.second->bins()) {
      const size_t idx = b.index();
      b.scaleW(1. / _axes[hist.first].width(idx));
    }
  }
}

///@}


/// @name Histograms
///@{
BinnedHistoPtr<int> _h_sig_rho, _h_sig_Kstar0;
BinnedHistoPtr<int> _h_mult_rho, _h_mult_Kstar0;
map<string, BinnedHistoPtr<string>> _h;
map<string, YODA::Axis<double>> _axes;
map<string, vector<string>> _edges;
///@}

};

RIVET_DECLARE_PLUGIN(HRS_1989_I276948);

} ```