Rivet analyses

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

namespace Rivet {


  /// @brief strange fraction at 7,8,13 TeV
  class LHCB_2019_I1760257 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2019_I1760257);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projection
      declare(UnstableParticles(), "UFS");

      for (double eVal : allowedEnergies()) {
        const int en(eVal + 0.5);
        if (isCompatibleWithSqrtS(eVal)) {
          if (en == 7000)
            _sqs = 0;
          else if (en == 8000)
            _sqs = 1;
          else
            _sqs = 2;
        }
      }
      raiseBeamErrorIf(_sqs < 0);
      //histograms
      for (size_t ix = 0; ix < 2; ++ix) {
        book(_c_B[ix], "TMP/c_B_" + toString(ix + 1), refData<YODA::BinnedEstimate<string>>(1, 1, 1));
        for (size_t iy = 0; iy < 3; ++iy) {
          book(_h_pT[ix][iy], "TMP/h_pT_" + toString(ix + 1) + "_" + toString(iy + 1), refData(5, 1, 1 + iy));
          book(_h_pL[ix][iy], "TMP/h_pL_" + toString(ix + 1) + "_" + toString(iy + 1), refData(3, 1, 1 + iy));
        }
        for (size_t iy = 0; iy < 5; ++iy) {
          book(_h_kin[ix][iy], "TMP/h_kin_" + toString(ix + 1) + "_" + toString(iy + 1),
               refData(4, 1, 1 + iy));
        }
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      if (_edges.empty()) _edges = _c_B[0]->xEdges();
      for (const Particle& p :
           apply<UnstableParticles>(event, "UFS").particles(Cuts::abspid == 521 or Cuts::abspid == 531)) {
        // kinematic region
        // rapidity cuts
        double y = p.rapidity(), eta = p.eta();
        if (y < 2. || y > 4.5 || eta < 2. || eta > 6.5) continue;
        // momentum cuts
        double pT = p.perp() / GeV, pL = p.momentum().z() / GeV, pTot = p.momentum().p3().mod() / GeV;
        if (pT < 0.5 || pT > 40. || pTot < 20. || pTot > 700. || pL < 20. || pL > 700.) continue;
        // type of meson
        unsigned int imeson = (p.abspid() % 100) / 10 - 2;
        _c_B[imeson]->fill(_edges[_sqs]);
        if (_sqs == 2) _c_B[imeson]->fill(_edges[3]);
        _h_pT[imeson][_sqs]->fill(pT);
        if (pL < 75.)
          _h_pL[imeson][0]->fill(pT);
        else if (pL < 125.)
          _h_pL[imeson][1]->fill(pT);
        else if (pL < 700.)
          _h_pL[imeson][2]->fill(pT);
        _h_kin[imeson][0]->fill(pTot);
        _h_kin[imeson][1]->fill(pL);
        _h_kin[imeson][2]->fill(pT);
        _h_kin[imeson][3]->fill(eta);
        _h_kin[imeson][4]->fill(y);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // ratio of branching ratios from PDSG 2020
      const double brRatio = 1.08e-3 / 1.02e-3;
      for (size_t iy = 0; iy < 5; ++iy) {
        Estimate1DPtr tmp;
        book(tmp, 4, 1, iy + 1);
        divide(_h_kin[1][iy], _h_kin[0][iy], tmp);
        tmp->scale(brRatio);
        if (iy >= 3) continue;
        book(tmp, 3, 1, iy + 1);
        divide(_h_pL[1][iy], _h_pL[0][iy], tmp);
        tmp->scale(brRatio);
        book(tmp, 5, 1, 1 + iy);
        divide(_h_pT[1][iy], _h_pT[0][iy], tmp);
        tmp->scale(brRatio);
      }
      // ratio
      BinnedEstimatePtr<string> ratio;
      book(ratio, 1, 1, 1);
      divide(_c_B[1], _c_B[0], ratio);
      ratio->scale(brRatio);
    }

    /// @}


    /// @name Histograms
    /// @{
    int _sqs = -1;
    vector<string> _edges;
    BinnedHistoPtr<string> _c_B[2];
    Histo1DPtr _h_pL[2][3], _h_kin[2][5], _h_pT[2][3];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(LHCB_2019_I1760257);

}