Rivet analyses

f2(1270), f0(980) and K2(1430)0 spectra at 29 GeV

Experiment: HRS (HRS)

Inspire ID: 18688

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 57 (1986) 1990

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: none listed

Measurement of the f2(1270), f0(980) and K2(1430)0 spectra at 29 GeV by the HRS experiment.

Source code:HRS_1986_I18688.cc

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

namespace Rivet {


  /// @brief f_2, f_0 and K_2 spectra at 29 GeV
  class HRS_1986_I18688 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1986_I18688);

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

    /// Book histograms and initialise projections before the run
    void init() {
      declare(UnstableParticles(), "UFS");
      book(_h_f2, 1, 1, 1);
      book(_h_f0, 1, 1, 2);
      book(_h_K2, 1, 1, 3);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      if (_edges.empty()) _edges = _h_f2->xEdges();
      UnstableParticles ufs = apply<UnstableParticles>(event, "UFS");
      for (const Particle& p :
           ufs.particles(Cuts::abspid == 9010221 || Cuts::abspid == 225 || Cuts::abspid == 315)) {
        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() == 225) {
          _h_f2->fill(map2string(xE), 1. / beta);
        }
        else if (p.pid() == 315) {
          _h_K2->fill(map2string(xE), 1. / beta);
        }
        else {
          _h_f0->fill(map2string(xE), 1. / beta);
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_h_f0, sqr(sqrtS()) * crossSection() / nanobarn / sumOfWeights());
      scale(_h_f2, sqr(sqrtS()) * crossSection() / nanobarn / sumOfWeights());
      scale(_h_K2, sqr(sqrtS()) * crossSection() / nanobarn / sumOfWeights());
      for (auto& hist : {_h_f0, _h_f2, _h_K2}) {
        for (auto& b : hist->bins()) {
          const size_t idx = b.index();
          b.scaleW(1. / _axis.width(idx));
        }
      }
    }

    ///@}

    string map2string(const double value) const {
      const size_t idx = _axis.index(value);
      if (idx && idx <= _edges.size()) return _edges[idx - 1];
      return "OTHER";
    }

    /// @name Histograms
    ///@{
    BinnedHistoPtr<string> _h_f0, _h_f2, _h_K2;
    YODA::Axis<double> _axis{0.1, 0.2, 0.3, 0.4, 0.7};
    vector<string> _edges;
    ///@}
  };


  RIVET_DECLARE_PLUGIN(HRS_1986_I18688);

}