Rivet analyses

Mass distributions in the decays B0 → D−D0K+ and B+ → D̄0D0K+

Experiment: BABAR (PEP-II)

Inspire ID: 1335269

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 91 (2015) 5, 052002

Beams: * *

Beam energies: ANY

Run details: - Any process producing B0 and B+, originally Upsilon(4S) decays

Mass distributions in the decays B0 → D−D0K+ and B+ → D̄0D0K+ the data were read from the plots in the paper and the backgrounds from the paper subtracted they may be be correct for efficiency.

Source code:BABAR_2015_I1335269.cc

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

namespace Rivet {


  /// @brief B -> D D K
  class BABAR_2015_I1335269 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2015_I1335269);


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

    /// Book histograms and initialise projections before the run
    void init() {
      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);
      declare(BB, "BB");
      // histograms
      for (unsigned int ix = 0; ix < 2; ++ix) {
        for (unsigned int iy = 0; iy < 3; ++iy) {
          book(_h[ix][iy], 1 + ix, 1, 1 + iy);
        }
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId, unsigned int>& mode1 = {{-411, 1}, {421, 1}, {321, 1}};
      static const map<PdgId, unsigned int>& mode1CC = {{411, 1}, {-421, 1}, {-321, 1}};
      static const map<PdgId, unsigned int>& mode2 = {{-421, 1}, {421, 1}, {321, 1}};
      static const map<PdgId, unsigned int>& mode2CC = {{421, 1}, {-421, 1}, {-321, 1}};
      DecayedParticles BB = apply<DecayedParticles>(event, "BB");
      for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
        int sign = 1, imode = 0;
        if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1)) {
          imode = 0;
          sign = 1;
        }
        else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1CC)) {
          imode = 0;
          sign = -1;
        }
        else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2)) {
          imode = 1;
          sign = 1;
        }
        else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2CC)) {
          imode = 1;
          sign = -1;
        }
        else
          continue;
        const Particle& D0 = BB.decayProducts()[ix].at(sign * 421)[0];
        const Particle& Kp = BB.decayProducts()[ix].at(sign * 321)[0];
        int iD = imode == 0 ? 411 : 421;
        const Particle& Dm = BB.decayProducts()[ix].at(-sign * iD)[0];
        _h[imode][0]->fill((D0.momentum() + Dm.momentum()).mass());
        _h[imode][1]->fill((Kp.momentum() + Dm.momentum()).mass());
        _h[imode][2]->fill((Kp.momentum() + D0.momentum()).mass());
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 2; ++ix) {
        for (unsigned int iy = 0; iy < 3; ++iy) {
          normalize(_h[ix][iy], 1., false);
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[2][3];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BABAR_2015_I1335269);

}