Rivet analyses

Mass distributions in the decays B⁰ → D_s⁻K_S⁰π⁺ and B⁺ → D_s⁻K⁺K⁺

Experiment: BELLE (KEKB)

Inspire ID: 1326905

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 91 (2015) 3, 032008

Beams: * *

Beam energies: ANY

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

Mass distributions in the decays B⁰ → D_s⁻K_S⁰π⁺ and B⁺ → D_s⁻K⁺K⁺, the data were read from the plots in the paper and although the backgrounds have been subtracted they may be be correct for efficiency.

Source code:`BELLE_2015_I1326905.cc`

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

namespace Rivet {


  /// @brief B0 ->\to Ds- KS0 pi+ and B+ -> Ds- K+ K^+ 
  class BELLE_2015_I1326905 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2015_I1326905);


    /// @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( 431);
      BB.addStable(-431);
      BB.addStable( 310);
      declare(BB, "BB");
      //histograms
      for(unsigned int ix=0;ix<2;++ix) {
    book(_h[ix],1,1,1+ix);
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId,unsigned int> & mode1   = { {-431,1},{ 310,1}, { 211,1}};
      static const map<PdgId,unsigned int> & mode1CC = { { 431,1},{ 310,1}, {-211,1}};
      static const map<PdgId,unsigned int> & mode2   = { {-431,1},{ 321,2}};
      static const map<PdgId,unsigned int> & mode2CC = { { 431,1},{-321,2}};
      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 & Ds  = BB.decayProducts()[ix].at(-sign*431)[0];
    FourMomentum pK;
    if(imode==0) {
      pK = BB.decayProducts()[ix].at(310)[0].momentum();
    }
    else {
      const Particles & Kp = BB.decayProducts()[ix].at(sign*321);
      pK = Kp[0].momentum().p3().mod()>Kp[1].momentum().p3().mod() ?
        Kp[1].momentum() : Kp[0].momentum();
    }
    _h[imode]->fill((Ds.momentum()+pK).mass());
      }
    }


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

    /// @}


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


  };


  RIVET_DECLARE_PLUGIN(BELLE_2015_I1326905);

}

Rivet analyses

Mass distributions in the decays B0 → Ds−KS0π+ and B+ → Ds−K+K+

Source code:BELLE_2015_I1326905.cc

Mass distributions in the decays B⁰ → D_s⁻K_S⁰π⁺ and B⁺ → D_s⁻K⁺K⁺

Source code:`BELLE_2015_I1326905.cc`