Rivet analyses

e⁺e⁻→ K⁺K⁻π⁺π⁻, K⁺K⁻π⁰π⁰ and K⁺K⁻K⁺K⁻ cross-sections between 1.4 and 4 GeV

Experiment: BABAR (PEP-II)

Inspire ID: 747875

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D76 (2007) 012008, 2007

Beams: e+ e-

Beam energies: ANY

Run details: - e+e- to hadrons

Measurement of the cross section for e⁺e⁻→ K⁺K⁻π⁺π⁻, K⁺K⁻π⁰π⁰ and K⁺K⁻K⁺K⁻ via radiative return, including the identification of K^*0, ϕ and f₀(980) mesons for energies between 1.4 and 4. GeV

Source code:`BABAR_2007_I747875.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_2007_I747875 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2007_I747875);


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

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

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

      book(_cKpKmpippim, "TMP/KpKmpippim");
      book(_cKstarKpi, "TMP/KstarKpi");
      book(_cphipippim, "TMP/phipippim");
      book(_cphif0, "TMP/phif0");
      book(_cKpKmpi0pi0, "TMP/KpKmpi0pi0");
      book(_cphif0pi0pi0, "TMP/phif0pi0pi0");
      book(_c2Kp2Km, "TMP/2Kp2Km");
    }

    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 (abs(p.pid()) == 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))
            _cKstarKpi->fill();
        }
        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) _cphipippim->fill();
          }
          for (const Particle& p2 : ufs.particles()) {
            if (p2.pid() != 9010221) 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) {
              _cphif0pi0pi0->fill();
              _cphif0->fill();
            }
          }
        }
      }
      if (ntotal == 4) {
        if (nCount[321] == 1 && nCount[-321] == 1 && nCount[211] == 1 && nCount[-211] == 1)
          _cKpKmpippim->fill();
        else if (nCount[321] == 1 && nCount[-321] == 1 && nCount[111] == 2)
          _cKpKmpi0pi0->fill();
        else if (nCount[321] == 2 && nCount[-321] == 2)
          _c2Kp2Km->fill();
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 1; ix < 8; ++ix) {
        double sigma = 0., error = 0.;
        if (ix == 1) {
          sigma = _cKpKmpippim->val();
          error = _cKpKmpippim->err();
        }
        else if (ix == 2) {
          sigma = _cKstarKpi->val();
          error = _cKstarKpi->err();
        }
        else if (ix == 3) {
          sigma = _cphipippim->val();
          error = _cphipippim->err();
        }
        else if (ix == 4) {
          sigma = _cphif0->val();
          error = _cphif0->err();
        }
        else if (ix == 5) {
          sigma = _cKpKmpi0pi0->val();
          error = _cKpKmpi0pi0->err();
        }
        else if (ix == 6) {
          sigma = _cphif0pi0pi0->val();
          error = _cphif0pi0pi0->err();
        }
        else if (ix == 7) {
          sigma = _c2Kp2Km->val();
          error = _c2Kp2Km->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 _cKpKmpippim, _cKstarKpi, _cphipippim, _cphif0, _cKpKmpi0pi0, _cphif0pi0pi0, _c2Kp2Km;
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BABAR_2007_I747875);


}

Rivet analyses

e+e−→ K+K−π+π−, K+K−π0π0 and K+K−K+K− cross-sections between 1.4 and 4 GeV

Source code:BABAR_2007_I747875.cc

e⁺e⁻→ K⁺K⁻π⁺π⁻, K⁺K⁻π⁰π⁰ and K⁺K⁻K⁺K⁻ cross-sections between 1.4 and 4 GeV

Source code:`BABAR_2007_I747875.cc`