Rivet analyses

Differential branching ratio w.r.t pp̄ mass for B+ → pp̄π+, K+, K*+ and B0 → pp̄KS0

Experiment: BELLE (KEKB)

Inspire ID: 630328

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 92 (2004) 131801

Beams: * *

Beam energies: ANY

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

Measurement of the differential branching ratio with respect to the pp̄ mass for B+ → pp̄π+, K+, K*+ and B0 → pp̄KS0. The data was taken from table 1 in the paper.

Source code:BELLE_2004_I630328.cc

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

namespace Rivet {


  /// @brief B+ -> p pbar pi+/K+/K*+ and B0 -> p pbar KS0
  class BELLE_2004_I630328 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2004_I630328);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
      declare(ufs, "UFS");
      DecayedParticles BB(ufs);
      BB.addStable(310);
      BB.addStable(323);
      BB.addStable(-323);
      declare(BB, "BB");
      // histograms
      for (unsigned int ix = 0; ix < 4; ++ix) {
        book(_h[ix], 1, 1, 1 + ix);
      }
      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) {
      DecayedParticles BB = apply<DecayedParticles>(event, "BB");
      // loop over particles
      for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
        int imode = 0;
        if (BB.decaying()[ix].abspid() == 511)
          _c[0]->fill();
        else
          _c[1]->fill();
        if ((BB.decaying()[ix].pid() == 521 && BB.modeMatches(ix, 3, mode1))
            || (BB.decaying()[ix].pid() == -521 && BB.modeMatches(ix, 3, mode1CC)))
          imode = 0;
        else if ((BB.decaying()[ix].pid() == 521 && BB.modeMatches(ix, 3, mode2))
                 || (BB.decaying()[ix].pid() == -521 && BB.modeMatches(ix, 3, mode2CC)))
          imode = 1;
        else if ((BB.decaying()[ix].pid() == 521 && BB.modeMatches(ix, 3, mode3))
                 || (BB.decaying()[ix].pid() == -521 && BB.modeMatches(ix, 3, mode3CC)))
          imode = 2;
        else if (BB.decaying()[ix].abspid() == 511 && BB.modeMatches(ix, 3, mode4))
          imode = 3;
        else {
          continue;
        }
        const Particle& pp = BB.decayProducts()[ix].at(2212)[0];
        const Particle& pbar = BB.decayProducts()[ix].at(-2212)[0];
        const double mass = (pp.mom() + pbar.mom()).mass();
        _h[imode]->fill(mass);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 4; ++ix) {
        if (ix == 2)
          scale(_h[ix], 1e6 / *_c[0]);
        else
          scale(_h[ix], 1e6 / *_c[1]);
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[4];
    CounterPtr _c[2];
    const map<PdgId, unsigned int> mode1 = {{2212, 1}, {-2212, 1}, {321, 1}};
    const map<PdgId, unsigned int> mode1CC = {{2212, 1}, {-2212, 1}, {-321, 1}};
    const map<PdgId, unsigned int> mode2 = {{2212, 1}, {-2212, 1}, {211, 1}};
    const map<PdgId, unsigned int> mode2CC = {{2212, 1}, {-2212, 1}, {-211, 1}};
    const map<PdgId, unsigned int> mode3 = {{2212, 1}, {-2212, 1}, {323, 1}};
    const map<PdgId, unsigned int> mode3CC = {{2212, 1}, {-2212, 1}, {-323, 1}};
    const map<PdgId, unsigned int> mode4 = {{2212, 1}, {-2212, 1}, {310, 1}};
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BELLE_2004_I630328);

}