Rivet analyses

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

namespace Rivet {


  /// @brief B -> K* l+ l-
  class BELLE_2019_I1728173 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2019_I1728173);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid==511 or
                        Cuts::abspid==521);
      declare(ufs, "UFS");
      DecayedParticles BB(ufs);
      BB.addStable(   443);
      BB.addStable(100443);
      BB.addStable( 313);
      BB.addStable( 323);
      BB.addStable(-313);
      BB.addStable(-323);
      declare(BB, "BB");
      // book histograms
      for(unsigned int ix=0;ix<4;++ix)
        for(unsigned int iy=0;iy<3;++iy) {
          book(_h_br[ix][iy],"TMP/h_br_"+toString(ix+1)+"_"+toString(iy+1),refData(1,1+iy,1));
        }
      for(unsigned int ix=0;ix<2;++ix)
        book(_c[ix],"TMP/nB_"+toString(ix+1));
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId,unsigned int> & mode1   = { { 323,1},{ 13,1}, {-13,1}};
      static const map<PdgId,unsigned int> & mode1CC = { {-323,1},{ 13,1}, {-13,1}};
      static const map<PdgId,unsigned int> & mode2   = { { 313,1},{ 13,1}, {-13,1}};
      static const map<PdgId,unsigned int> & mode2CC = { {-313,1},{ 13,1}, {-13,1}};
      static const map<PdgId,unsigned int> & mode3   = { { 323,1},{ 11,1}, {-11,1}};
      static const map<PdgId,unsigned int> & mode3CC = { {-323,1},{ 11,1}, {-11,1}};
      static const map<PdgId,unsigned int> & mode4   = { { 313,1},{ 11,1}, {-11,1}};
      static const map<PdgId,unsigned int> & mode4CC = { {-313,1},{ 11,1}, {-11,1}};
      DecayedParticles BB = apply<DecayedParticles>(event, "BB");
      // loop over particles
      for(unsigned int ix=0;ix<BB.decaying().size();++ix) {
        if(BB.decaying()[ix].abspid()==521) _c[0]->fill();
        else                                _c[1]->fill();
        int imode=0;
        if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode1)) ||
        (BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode1CC)))       imode=0;
    else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode2)) ||
         (BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode2CC)))  imode=1;
        else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode3)) ||
         (BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode3CC)))  imode=2;
        else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode4)) ||
         (BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode4CC)))  imode=3;
        else continue;
        int il = imode<2 ? 13 : 11;
        const Particle & lp = BB.decayProducts()[ix].at(-il)[0];
        const Particle & lm = BB.decayProducts()[ix].at( il)[0];
        double qq = (lp.momentum()+lm.momentum()).mass2();
        for(unsigned int iy=0;iy<3;++iy) {
          _h_br[imode][iy]->fill(qq);
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // ratio of lifetimes
      double rLife = 1.078;
      // normalize BR plots
      for(unsigned int ix=0;ix<4;++ix) {
        for(unsigned int iy=0;iy<3;++iy) {
          if(ix%2==0) {
             scale(_h_br[ix][iy],1e7/ *_c[0]);
          }
          else {
             scale(_h_br[ix][iy],1e7*rLife/ *_c[1]);
          }
        }
      }
      // RK*
      for (unsigned int ix=0;ix<3;++ix) {
        Estimate1DPtr RK;
        book(RK,1,1+ix,3);
        divide(_h_br[0][ix],_h_br[2][ix],RK);
        book(RK,1,1+ix,2);
        divide(_h_br[1][ix],_h_br[3][ix],RK);
        book(RK,1,1+ix,1);
        size_t iloc=1;
        for (size_t ibin=0; ibin < _h_br[1][ix]->numBins(); ++ibin) {
          while(_h_br[0][ix]->bin(iloc).isMasked()) ++iloc;
          double num     = _h_br[0][ix]->bin(iloc).sumW()   +_h_br[1][ix]->bin(iloc).sumW();
          double numErr2 = sqr(_h_br[0][ix]->bin(iloc).errW())+sqr(_h_br[1][ix]->bin(iloc).errW());
          double den     = _h_br[2][ix]->bin(iloc).sumW()   +_h_br[3][ix]->bin(iloc).sumW();
          double denErr2 = sqr(_h_br[2][ix]->bin(iloc).errW())+sqr(_h_br[3][ix]->bin(iloc).errW());
          double val(0.),err(0.);
          if(num>0. && den>0.) {
            val = num/den;
            err = val*(numErr2/sqr(num)+denErr2/sqr(den));
          }
          RK->bin(iloc).set(val, err);
          ++iloc;
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    CounterPtr _c[2];
    Histo1DPtr _h_br[4][3];
    /// @}

  };


  RIVET_DECLARE_PLUGIN(BELLE_2019_I1728173);

}