Rivet analyses

title: BELLE_2015_I1358399

Cross section for $B_s^{()0}\bar{B}_s^{()0}$ 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 $B_s^{()0}\bar{B}_s^{()0}$ at $\sqrt{s}=10.86$ GeV.

Source code:BELLE_2015_I1358399.cc

```c++ // -- 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 (const auto& 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);

} ```