Rivet analyses

Cross Section for e⁺e⁻→ K⁺K⁻η, K⁺K⁻π⁰ and K_S⁰K^±π^∓ from threshold to 4.6 GeV

Experiment: BABAR (PEP-II)

Inspire ID: 765258

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D77 (2008) 092002, 2008

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Measurement of the cross section for e⁺e⁻→ K⁺K⁻η, K⁺K⁻π⁰ and K_S⁰K^±π^∓ via radiative return, including the identification of ϕ and η mesons for energies from threshold to 4.6 GeV.

Source code:`BABAR_2008_I765258.cc`

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

namespace Rivet {


  /// @brief Add a short analysis description here
  class BABAR_2008_I765258 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2008_I765258);


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

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

      // Initialise and register projections
      declare(FinalState(), "FS");
      declare(UnstableParticles(), "UFS");

      // Book histograms
      for (unsigned int ix = 1; ix < 6; ++ix) {
        stringstream ss;
        ss << "TMP/n" << ix;
        book(_nMeson[ix], ss.str());
      }
    }

    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(Cuts::pid == 221 or Cuts::pid == 333)) {
        if (p.children().empty()) continue;
        map<long, int> nRes = nCount;
        int ncount = ntotal;
        findChildren(p, nRes, ncount);

        if (p.pid() == 221) {
          bool matchedKK = false;
          if (ncount == 2) {
            matchedKK = true;
            for (const auto& val : nRes) {
              if (abs(val.first) == 321) {
                if (val.second != 1) {
                  matchedKK = false;
                  break;
                }
              }
              else if (val.second != 0) {
                matchedKK = false;
                break;
              }
            }
          }
          if (matchedKK) _nMeson[4]->fill();
          for (const Particle& p2 : ufs.particles()) {
            if (p2.pid() != 333) 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) {
              _nMeson[5]->fill();
              break;
            }
          }
        }
        else if (p.pid() == 333) {
          if (ncount != 1) continue;
          bool matched = true;
          for (const auto& val : nRes) {
            if (val.first == 111) {
              if (val.second != 1) {
                matched = false;
                break;
              }
            }
            else if (val.second != 0) {
              matched = false;
              break;
            }
          }
          if (matched) _nMeson[3]->fill();
        }
      }


      if (ntotal == 3 && nCount[310] == 1
          && ((nCount[211] == 1 && nCount[-321] == 1) || (nCount[-211] == 1 && nCount[321] == 1)))
        _nMeson[1]->fill();
      else if (ntotal == 3 && nCount[321] == 1 && nCount[-321] == 1 && nCount[111] == 1)
        _nMeson[2]->fill();
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 1; ix < 6; ++ix) {
        double sigma = _nMeson[ix]->val();
        double error = _nMeson[ix]->err();
        sigma *= crossSection() / sumOfWeights() / nanobarn;
        error *= crossSection() / sumOfWeights() / nanobarn;
        Estimate1DPtr mult;
        book(mult, ix, 1, 1);
        for (auto& b : mult->bins()) {
          if (inRange(sqrtS() / GeV, b.xMin(), b.xMax())) {
            b.set(sigma, error);
          }
        }
      }
    }

    /// @}


    /// @name Histograms
    /// @{
    CounterPtr _nMeson[6];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BABAR_2008_I765258);

}

Rivet analyses

Cross Section for e+e−→ K+K−η, K+K−π0 and KS0K±π∓ from threshold to 4.6 GeV

Source code:BABAR_2008_I765258.cc

Cross Section for e⁺e⁻→ K⁺K⁻η, K⁺K⁻π⁰ and K_S⁰K^±π^∓ from threshold to 4.6 GeV

Source code:`BABAR_2008_I765258.cc`