Rivet analyses

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

namespace Rivet {


  /// @brief Bbar0 -> Lambda_c+ pbar pi+ pi-
  class BABAR_2013_I1217425 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2013_I1217425);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511);
      declare(ufs, "UFS");
      DecayedParticles B0(ufs);
      // treat Lambda_c, Sigma_c and sigma_c* as stable
      B0.addStable(4122);
      B0.addStable(-4122);
      B0.addStable(4112);
      B0.addStable(-4112);
      B0.addStable(4212);
      B0.addStable(-4212);
      B0.addStable(4222);
      B0.addStable(-4222);
      B0.addStable(4114);
      B0.addStable(-4114);
      B0.addStable(4214);
      B0.addStable(-4214);
      B0.addStable(4224);
      B0.addStable(-4224);
      declare(B0, "B0");
      // histograms
      for (unsigned int ix = 0; ix < 5; ++ix) {
        for (unsigned int iy = 0; iy < 6; ++iy) {
          if ((ix < 3 && iy >= 3) or (ix == 4 && iy >= 4)) continue;
          book(_h[ix][iy], 1 + ix, 1, 1 + iy);
        }
      }
    }


    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode1 = {{4112, 1}, {-2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode1CC = {{-4112, 1}, {2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode2 = {{4222, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode2CC = {{-4222, 1}, {2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode3 = {{4224, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode3CC = {{-4224, 1}, {2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode4 = {{4122, 1}, {-2212, 1}, {211, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode4CC = {{-4122, 1}, {2212, 1}, {211, 1}, {-211, 1}};
      DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
      // loop over particles
      for (unsigned int ix = 0; ix < B0.decaying().size(); ++ix) {
        int sign = 1, imode = -1, ibaryon, ipi = -211;
        if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode1)) {
          sign = 1;
          imode = 0;
          ibaryon = 4112;
          ipi = 211;
        }
        else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode1CC)) {
          sign = -1;
          imode = 0;
          ibaryon = 4112;
          ipi = 211;
        }
        else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode2)) {
          sign = 1;
          imode = 1;
          ibaryon = 4222;
        }
        else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode2CC)) {
          sign = -1;
          imode = 1;
          ibaryon = 4222;
        }
        else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode3)) {
          sign = 1;
          imode = 2;
          ibaryon = 4224;
        }
        else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode3CC)) {
          sign = -1;
          imode = 2;
          ibaryon = 4224;
        }
        else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 4, mode4)) {
          sign = 1;
          imode = 3;
          ibaryon = 4122;
        }
        else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 4, mode4CC)) {
          sign = -1;
          imode = 3;
          ibaryon = 4122;
        }
        else
          continue;
        const Particle& SigC = B0.decayProducts()[ix].at(sign * ibaryon)[0];
        const Particle& pbar = B0.decayProducts()[ix].at(-sign * 2212)[0];
        const Particle& pim = B0.decayProducts()[ix].at(sign * ipi)[0];
        if (imode <= 2) {
          _h[imode][0]->fill((SigC.momentum() + pim.momentum()).mass());
          _h[imode][1]->fill((SigC.momentum() + pbar.momentum()).mass());
          _h[imode][2]->fill((pbar.momentum() + pim.momentum()).mass());
        }
        else {
          const Particle& pip = B0.decayProducts()[ix].at(-sign * ipi)[0];
          _h[imode][0]->fill((SigC.momentum() + pip.momentum()).mass());
          _h[imode][1]->fill((SigC.momentum() + pim.momentum()).mass());
          _h[imode][2]->fill((pbar.momentum() + pip.momentum()).mass());
          _h[imode][3]->fill((pbar.momentum() + pim.momentum()).mass());
          FourMomentum ppipi = pip.momentum() + pim.momentum();
          _h[imode][4]->fill(ppipi.mass());
          FourMomentum plam = SigC.momentum() + pbar.momentum();
          _h[imode][5]->fill(plam.mass());
          _h[4][0]->fill((ppipi + pbar.momentum()).mass());
          _h[4][1]->fill((ppipi + SigC.momentum()).mass());
          _h[4][2]->fill((plam + pim.momentum()).mass());
          _h[4][3]->fill((plam + pip.momentum()).mass());
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 5; ++ix) {
        for (unsigned int iy = 0; iy < 6; ++iy) {
          if ((ix < 3 && iy >= 3) or (ix == 4 && iy >= 5)) continue;
          normalize(_h[ix][iy], 1., false);
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[5][6];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BABAR_2013_I1217425);

}