Rivet analyses

Charged particle momentum distributions for energies between 3.0 and 7.4 GeV

Experiment: MARK-I (SPEAR)

Inspire ID: 109792

Status: VALIDATED

Authors: - Peter Richardson

References: none listed

Beams: e- e+

Beam energies: (1.5, 1.5); (2.4, 2.4); (2.9, 2.9); (3.1, 3.1); (3.3, 3.3); (3.5, 3.5); (3.7, 3.7)GeV

Run details: - e+e- > hadrons.

Charged particle momentum distributions for energies between 3.0 and 7.4 GeV.

Source code:MARKI_1976_I109792.cc

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

namespace Rivet {


  /// @brief Charged particle spectra between 3.0 and 7.4 GeV
  class MARKI_1976_I109792 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(MARKI_1976_I109792);


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

    /// Book histograms and initialise projections before the run
    void init() {
      declare(ChargedFinalState(), "FS");
      unsigned int ih = 8;
      for (double eVal : allowedEnergies()) {
        const string en = toString(round(eVal/MeV));
        if (isCompatibleWithSqrtS(eVal))  _sqs = en;
        book(_h[en], ih--, 1, 1);
      }
      raiseBeamErrorIf(_sqs.empty());
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const ChargedFinalState& fs = apply<ChargedFinalState>(event, "FS");
      if (fs.particles().size()==2 && fs.particles()[0].abspid()==13 && fs.particles()[1].abspid()==13) vetoEvent;
      for (const Particle& p : fs.particles()) {
        const Vector3 mom3 = p.p3();
        double pp = mom3.mod();
        double x = 2.*pp/sqrtS();
        _h[_sqs]->fill(x);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (auto& item : _h) {
        const double en = stod(item.first.substr(0,4))*MeV;
        scale(item.second, crossSection()*sqr(en)/sumOfWeights()/microbarn);
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    map<string,Histo1DPtr> _h;
    string _sqs = "";
    /// @}


  };


  RIVET_DECLARE_PLUGIN(MARKI_1976_I109792);
}