Rivet analyses

Mass distributions in B → D(*)p + pions

Experiment: BABAR (PEP-II)

Inspire ID: 946659

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 85 (2012) 092017

Beams: * *

Beam energies: ANY

Run details: - Any process producing B mesons, original e+e- at Upsilon(4S)

Measurements of mass distributions in Mass distributions in B → D(*)p + pions. The data were read from the plots in the paper but are background subtracted and efficiency corrected.

Source code:BABAR_2012_I946659.cc

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

namespace Rivet {


  /// @brief B -> p pbar + pions
  class BABAR_2012_I946659 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I946659);


    /// @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(411);
      BB.addStable(-411);
      BB.addStable(421);
      BB.addStable(-421);
      BB.addStable(413);
      BB.addStable(-413);
      BB.addStable(423);
      BB.addStable(-423);
      declare(BB, "BB");
      // histograms
      for (unsigned int iy = 0; iy < 4; ++iy) {
        for (unsigned int ix = 0; ix < 4; ++ix) {
          if (ix < 2) book(_h[ix][iy], 1, 1 + ix, 1 + iy);
          book(_h[ix + 2][iy], 2, 1 + ix, 1 + iy);
          book(_h[ix + 6][iy], 3, 1 + ix, 1 + iy);
        }
      }
      book(_nB[0], "/TMP/nB0");
      book(_nB[1], "/TMP/nBP");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode1 = {{421, 1}, {2212, 1}, {-2212, 1}};
      static const map<PdgId, unsigned int>& mode1CC = {{-421, 1}, {2212, 1}, {-2212, 1}};
      static const map<PdgId, unsigned int>& mode2 = {{423, 1}, {2212, 1}, {-2212, 1}};
      static const map<PdgId, unsigned int>& mode2CC = {{-423, 1}, {2212, 1}, {-2212, 1}};
      static const map<PdgId, unsigned int>& mode3 = {{411, 1}, {2212, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode3CC = {{-411, 1}, {2212, 1}, {-2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode4 = {{413, 1}, {2212, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode4CC = {{-413, 1}, {2212, 1}, {-2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode5 = {{421, 1}, {2212, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode5CC = {{-421, 1}, {2212, 1}, {-2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode6 = {{423, 1}, {2212, 1}, {-2212, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode6CC = {{-423, 1}, {2212, 1}, {-2212, 1}, {211, 1}};
      static const map<PdgId, unsigned int>& mode7 = {{421, 1}, {2212, 1}, {-2212, 1}, {211, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode7CC = {{-421, 1},
                                                        {2212, 1},
                                                        {-2212, 1},
                                                        {211, 1},
                                                        {-211, 1}};
      static const map<PdgId, unsigned int>& mode8 = {{423, 1}, {2212, 1}, {-2212, 1}, {211, 1}, {-211, 1}};
      static const map<PdgId, unsigned int>& mode8CC = {{-423, 1},
                                                        {2212, 1},
                                                        {-2212, 1},
                                                        {211, 1},
                                                        {-211, 1}};
      static const map<PdgId, unsigned int>& mode9 = {{411, 1}, {2212, 1}, {-2212, 1}, {211, 2}};
      static const map<PdgId, unsigned int>& mode9CC = {{-411, 1}, {2212, 1}, {-2212, 1}, {211, 2}};
      static const map<PdgId, unsigned int>& mode10 = {{413, 1}, {2212, 1}, {-2212, 1}, {-211, 2}};
      static const map<PdgId, unsigned int>& mode10CC = {{-413, 1}, {2212, 1}, {-2212, 1}, {211, 2}};
      DecayedParticles BB = apply<DecayedParticles>(event, "BB");
      // loop over particles
      for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
        int sign = 1, imode = -1, idd = 421;
        if (BB.decaying()[ix].abspid() == 511) {
          _nB[0]->fill();
          if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1)) {
            sign = 1;
            imode = 0;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1CC)) {
            sign = -1;
            imode = 0;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2)) {
            sign = 1;
            imode = 1;
            idd = 423;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2CC)) {
            sign = -1;
            imode = 1;
            idd = 423;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode3)) {
            sign = 1;
            imode = 2;
            idd = 411;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode3CC)) {
            sign = -1;
            imode = 2;
            idd = 411;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode4)) {
            sign = 1;
            imode = 3;
            idd = 413;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode4CC)) {
            sign = -1;
            imode = 3;
            idd = 413;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 5, mode7)) {
            sign = 1;
            imode = 6;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 5, mode7CC)) {
            sign = -1;
            imode = 6;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 5, mode8)) {
            sign = 1;
            imode = 7;
            idd = 423;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 5, mode8CC)) {
            sign = -1;
            imode = 7;
            idd = 423;
          }
          else
            continue;
        }
        else {
          _nB[1]->fill();
          if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode5)) {
            sign = 1;
            imode = 4;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode5CC)) {
            sign = -1;
            imode = 4;
            idd = 421;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode6)) {
            sign = 1;
            imode = 5;
            idd = 423;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode6CC)) {
            sign = -1;
            imode = 5;
            idd = 423;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 5, mode9)) {
            sign = 1;
            imode = 8;
            idd = 411;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 5, mode9CC)) {
            sign = -1;
            imode = 8;
            idd = 411;
          }
          else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 5, mode10)) {
            sign = 1;
            imode = 9;
            idd = 413;
          }
          else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 5, mode10CC)) {
            sign = -1;
            imode = 9;
            idd = 413;
          }
          else
            continue;
        }
        const Particle& DD = BB.decayProducts()[ix].at(sign * idd)[0];
        const Particle& pp = BB.decayProducts()[ix].at(sign * 2212)[0];
        const Particle& pbar = BB.decayProducts()[ix].at(-sign * 2212)[0];
        double mppbar = (pp.momentum() + pbar.momentum()).mass();
        double mpD = (pp.momentum() + DD.momentum()).mass();
        if (imode == 0) {
          if (sqr(mppbar) > 5.)
            _h[0][0]->fill(mpD);
          else
            _h[0][1]->fill(mpD);
          if (sqr(mpD) > 9.)
            _h[0][2]->fill(mppbar);
          else
            _h[0][3]->fill(mppbar);
        }
        else if (imode == 1) {
          if (sqr(mppbar) > 5.)
            _h[1][0]->fill(mpD);
          else
            _h[1][1]->fill(mpD);
          if (sqr(mpD) > 10.5)
            _h[1][2]->fill(mppbar);
          else
            _h[1][3]->fill(mppbar);
        }
        else {
          _h[imode][0]->fill(mppbar);
          _h[imode][1]->fill((pbar.momentum() + DD.momentum()).mass());
          _h[imode][2]->fill(mpD);
          const Particles& pim = BB.decayProducts()[ix].at(-sign * 211);
          for (unsigned int iy = 0; iy < pim.size(); ++iy) {
            _h[imode][3]->fill((pp.momentum() + pim[iy].momentum()).mass());
          }
          if (imode == 6 || imode == 7) {
            const Particle& pip = BB.decayProducts()[ix].at(sign * 211)[0];
            _h[imode][3]->fill((pp.momentum() + pip.momentum()).mass());
          }
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 10; ++ix) {
        CounterPtr temp = (ix < 4 || ix == 6 || ix == 7) ? _nB[0] : _nB[1];
        for (unsigned int iy = 0; iy < 4; ++iy) {
          if (iy == 3 && ix > 5)
            scale(_h[ix][iy], 0.5e5 / *temp);
          else
            scale(_h[ix][iy], 1e5 / *temp);
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[10][4];
    CounterPtr _nB[2];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BABAR_2012_I946659);

}