Rivet analyses

Cross section for Bs(*)0B̄s(*)0 at $\sqrt{s}=10.859$ GeV

Experiment: CLEOIII (CESR)

Inspire ID: 694869

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 96 (2006) 022002

Beams: e+ e-

Beam energies: (5.4, 5.4)GeV

Run details: - e+e- > hadrons

Measurement of the cross section for Bs(*)0B̄s(*)0 at $\sqrt{s}=10.859$ GeV.

Source code:CLEOIII_2006_I694869.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 CLEOIII_2006_I694869 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEOIII_2006_I694869);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(Cuts::abspid == 533), "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();
      for (const Particle& p1 : bHadrons) {
        if (p1.pid() < 0 || p1.parents()[0].abspid() == 533) continue;
        map<long, int> nRes = nCount;
        int ncount = ntotal;
        findChildren(p1, nRes, ncount);
        bool matched = false;
        for (const Particle& p2 : bHadrons) {
          if (p1.pid() != -p2.pid() || p2.parents()[0].abspid() == 533) continue;
          map<long, int> nRes2 = nRes;
          int ncount2 = ncount;
          findChildren(p2, nRes2, ncount2);
          if (ncount2 != 0) continue;
          matched = true;
          for (const auto& val : nRes2) {
            if (val.second != 0) {
              matched = false;
              break;
            }
          }
          if (matched) {
            _h->fill("10.859"s);
            break;
          }
        }
        if (matched) break;
      }
    }


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

    /// @}


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


  RIVET_DECLARE_PLUGIN(CLEOIII_2006_I694869);

}