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);

}