Rivet analyses

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

namespace Rivet {


  /// @brief Lambda_c+ at 5.02 TeV
  class ALICE_2021_I1829739 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(ALICE_2021_I1829739);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projection
      declare(UnstableParticles(), "UFS");
      // histograms
      book(_h_Lambda,1,1,1);
      book(_h_D     ,"TMP/h_D",refData(4,1,1));
      book(_h_sig[0],7,1,1);
      book(_h_sig[1],7,1,2);
      book(_c_D,"TMP/c_D");
      book(_c_Lambda,"TMP/c_Lambda");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // Final state of unstable particles to get particle spectra
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      // loop over onium states
      for (const Particle & p : ufs.particles(Cuts::abspid==4122 || Cuts::abspid==421)) {
        // prompt
        if (p.fromBottom()) continue;
        // skip copies due mixing
        if (p.children().size()==1 && p.children()[0].abspid()==p.abspid()) continue;
        if (p.absrap()>.5) continue;
        const double pT = p.perp();
        if (p.abspid()==4122) {
          _h_Lambda->fill(pT);
          if (pT>1. && pT<12.) _h_sig[0]->fill("P P --> Lc X"s);
          _h_sig[1]->fill("P P --> Lc X"s);
          _c_Lambda->fill();
        }
        else {
          _h_D->fill(pT);
          _c_D->fill();
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      double factor = crossSection()/microbarn/sumOfWeights();
      scale(_h_Lambda,factor);
      scale(_h_D     ,factor);
      scale(_h_sig,factor);

      Estimate1DPtr tmp;
      // ratio prompt Lambda/D0
      book(tmp,4,1,1);
      divide(_h_Lambda,_h_D,tmp);

      // ratio lambda/D0 integrated
      Estimate0D e0d = *_c_Lambda / *_c_D;
      BinnedEstimatePtr<string> ratio;
      book(ratio, 8, 1, 1);
      auto& b = ratio->bin(1);
      b.setVal(e0d.val());
      if(e0d.numErrs()!=0) b.setErr(e0d.err());
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_Lambda,_h_D;
    BinnedHistoPtr<string> _h_sig[2];
    CounterPtr _c_D,_c_Lambda;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(ALICE_2021_I1829739);

}