Rivet analyses

title: BABAR_2012_I892684

Cross sections for $e^+e^-\to$ $K^+K^-\pi^+\pi^-$, $K^+K^-\pi^0\pi^0$, and $K^+K^-K^+K^-$ between 1.28 and 5.0 GeV

Experiment: BABAR (PEP-II)

Inspire ID: 892684

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D86 (2012) 012008, 2012

Beams: e+ e-

Beam energies: (0.6, 0.6); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.7, 0.7); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.8, 0.8); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (0.9, 0.9); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.0, 1.0); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.1, 1.1); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.2, 1.2); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.3, 1.3); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.4, 1.4); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.5, 1.5); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.6, 1.6); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.7, 1.7); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.8, 1.8); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (1.9, 1.9); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.0, 2.0); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.1, 2.1); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.2, 2.2); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.3, 2.3); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.4, 2.4); (2.5, 2.5); (2.5, 2.5); (2.5, 2.5); (2.5, 2.5)GeV

Run details: - e+e- to hadrons

Measurement of the cross section for $e^+e^- \to$ $K^+K^-\pi^+\pi^-$, $K^+K^-\pi^0\pi^0$ and $K^+K^-K^+K^-$ via radiative return, including the identification of $K^{*0}$, $\phi$ and $f_0(980)$ mesons for energies between 1.28 and 5.0 GeV.

Source code:BABAR_2012_I892684.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief e+e- > K+K- + pi+pi-, pi0pi0 or K+K- class BABAR_2012_I892684 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I892684);


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

/// Book histograms and initialise projections before the run
void init() {

  // Initialise and register projections
  declare(FinalState(), "FS");
  declare(UnstableParticles(), "UFS");
  bool matched = false;
  for (size_t ix = 0; ix < _sqs.size(); ++ix) {
    book(_sigma[ix], 1 + ix, 1, 1);
    for (const string& en : _sigma[ix].binning().edges<0>()) {
      const double eval = stod(en) * GeV;
      if (isCompatibleWithSqrtS(eval)) {
        _sqs[ix] = en;
        matched = true;
        break;
      }
    }
  }
  raiseBeamErrorIf(!matched);
}

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;
  }
  const FinalState& ufs = apply<FinalState>(event, "UFS");
  for (const Particle& p : ufs.particles()) {
    if (p.children().empty()) continue;
    // K*0
    if (p.abspid() == 313) {
      map<long, int> nRes = nCount;
      int ncount = ntotal;
      findChildren(p, nRes, ncount);
      // K* K+/- pi-/+
      if (ncount != 2) continue;
      bool matched = true;
      for (const auto& val : nRes) {
        if (abs(val.first) == 321 || abs(val.first) == 211) {
          continue;
        }
        else if (val.second != 0) {
          matched = false;
          break;
        }
      }
      if (matched == false) continue;
      if ((nCount[321] == 1 && nCount[-321] == 0 && nCount[211] == 0 && nCount[-211] == 1)
          || (nCount[321] == 0 && nCount[-321] == 1 && nCount[211] == 1 && nCount[-211] == 0)) {
        if (!_sqs[1].empty()) _sigma[1]->fill(_sqs[1]);
      }
    }
    else if (p.pid() == 333) {
      map<long, int> nRes = nCount;
      int ncount = ntotal;
      findChildren(p, nRes, ncount);
      // phi pi+pi-
      if (ncount == 2) {
        bool matched = true;
        for (const auto& val : nRes) {
          if (abs(val.first) == 211) {
            if (val.second != 1) {
              matched = false;
              break;
            }
          }
          else if (val.second != 0) {
            matched = false;
            break;
          }
        }
        if (matched) {
          if (!_sqs[2].empty()) _sigma[2]->fill(_sqs[2]);
        }
      }
      for (const Particle& p2 : ufs.particles()) {
        if (p2.pid() != 9010221 && p2.pid() != 9000221) continue;
        if (p2.parents()[0].isSame(p)) continue;
        map<long, int> nResB = nRes;
        int ncountB = ncount;
        findChildren(p2, nResB, ncountB);
        if (ncountB != 0) continue;
        bool matched2 = true;
        for (const auto& val : nResB) {
          if (val.second != 0) {
            matched2 = false;
            break;
          }
        }
        if (matched2) {
          if (p2.pid() == 9010221) {
            if (!_sqs[6].empty()) _sigma[6]->fill(_sqs[6]);
            if (!_sqs[3].empty()) _sigma[3]->fill(_sqs[3]);
          }
          else {
            if (!_sqs[4].empty()) _sigma[4]->fill(_sqs[4]);
          }
        }
      }
    }
  }
  if (ntotal == 4) {
    if (nCount[321] == 1 && nCount[-321] == 1 && nCount[211] == 1 && nCount[-211] == 1) {
      if (!_sqs[0].empty()) _sigma[0]->fill(_sqs[0]);
    }
    else if (nCount[321] == 1 && nCount[-321] == 1 && nCount[111] == 2) {
      if (!_sqs[5].empty()) _sigma[5]->fill(_sqs[5]);
    }
    else if (nCount[321] == 2 && nCount[-321] == 2) {
      if (!_sqs[7].empty()) _sigma[7]->fill(_sqs[7]);
    }
  }
}


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

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<string> _sigma[8];
vector<string> _sqs = vector<string>(8, ""s);
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2012_I892684);

} ```