Rivet analyses

Cross section for e+e− → π+π− below 0.93 GeV

Experiment: KLOE (DAPHNE)

Inspire ID: 797438

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Lett. B670 (2009) 285-291, 2009

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Measurement of the cross section for e+e− → π+π− below 0.93 GeV

Source code:KLOE_2009_I797438.cc

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

namespace Rivet {


  /// @brief e+e- -> pi+pi-
  class KLOE_2009_I797438 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(KLOE_2009_I797438);


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

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

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

      // Book histograms
      book(_npion, "TMP/pion", refData(1,1,1));

    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");
      if(fs.particles().size()!=2) vetoEvent;
      for (const Particle& p : fs.particles()) {
    if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
      }
      _npion->fill(sqr(sqrtS()/GeV));
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_npion, crossSection()/ sumOfWeights() /nanobarn);
      Estimate1DPtr mult;
      book(mult, 2, 1, 1);
      barchart(_npion,mult);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _npion;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(KLOE_2009_I797438);


}