Rivet analyses

Cross section for Bs(*)0B̄s(*)0 at $\sqrt{s}=10.86$ GeV

Experiment: BELLE (KEKB)

Inspire ID: 1358399

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 92 (2015) 7, 072013

Beams: e+ e-

Beam energies: (5.4, 5.4)GeV

Run details: none listed

Measurement of the cross section for Bs(*)0B̄s(*)0 at $\sqrt{s}=10.86$ GeV.

Source code:BELLE_2015_I1358399.cc

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

namespace Rivet {


  /// @brief e+ e- > B(*)s B(*)s
  class BELLE_2015_I1358399 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2015_I1358399);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");
      // histograms
      book(_h,1,1,1);
    }

    void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
      for (const Particle &child : p.children()) {
        if (child.children().empty()) {
          nRes[child.pid()]-=1;
          --ncount;
        }
        else {
          findChildren(child,nRes,ncount);
        }
      }
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& fs = apply<FinalState>(event, "FS");

      map<long,int> nCount;
      int ntotal(0);
      for (const Particle& p : fs.particles()) {
        nCount[p.pid()] += 1;
        ++ntotal;
      }
      // extract botton hadrons
      Particles bHadrons=apply<FinalState>(event, "UFS").particles(Cuts::abspid==531 or Cuts::abspid==533);
      for (unsigned int ix=0;ix<bHadrons.size();++ix) {
        if (bHadrons[ix].parents()[0].abspid()==531 ||
            bHadrons[ix].parents()[0].abspid()==533 ) continue;
        map<long,int> nRes = nCount;
        int ncount = ntotal;
        findChildren(bHadrons[ix],nRes,ncount);
        bool matched=false;
        for (unsigned int iy=ix+1;iy<bHadrons.size();++iy) {
          if (bHadrons[iy].parents()[0].abspid()==531 ||
             bHadrons[iy].parents()[0].abspid()==533 ) continue;
          map<long,int> nRes2 = nRes;
          int ncount2 = ncount;
          findChildren(bHadrons[iy],nRes2,ncount2);
          if (ncount2!=0) continue;
          matched=true;
          for(auto const & val : nRes2) {
            if(val.second!=0) {
              matched = false;
              break;
            }
          }
          if (matched) {
            _h->fill("10.86"s);
            break;
          }
        }
        if (matched) break;
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_h, crossSection()/ sumOfWeights() /picobarn);
    }

    /// @}


    /// @name Histograms
    /// @{
    BinnedHistoPtr<string> _h;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BELLE_2015_I1358399);

}