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## Rivet analyses reference

### BABAR_2020_I1769654

Cross section for $e^+e^-\to K_S^0K_L^0$ between 1.98 and 2.26 GeV
Experiment: BABAR (PEP-II)
Inspire ID: 1769654
Status: VALIDATED
Authors:
• Peter Richardson
References:
• Phys.Rev. D101 (2020) no.1, 012011
Beams: * *
Beam energies: ANY
Run details:
Measurement of the cross section for $e^+e^-\to$ $K_S^0K_L^0$ via radiative return, including for energies between 1.98 and 2.26 GeV, N.B. the result is consistent with zero cross section
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 // -*- C++ -*- #include "Rivet/Analysis.hh" #include "Rivet/Projections/FinalState.hh" namespace Rivet { /// @brief e+e- > K0S K0L class BABAR_2020_I1769654 : public Analysis { public: /// Constructor DEFAULT_RIVET_ANALYSIS_CTOR(BABAR_2020_I1769654); /// @name Analysis methods ///@{ /// Book histograms and initialise projections before the run void init() { // Initialise and register projections declare(FinalState(), "FS"); // Book histograms book(_nKSKL , "TMP/nKSKL"); } /// Perform the per-event analysis void analyze(const Event& event) { const FinalState& fs = apply(event, "FS"); map nCount; int ntotal(0); for (const Particle& p : fs.particles()) { nCount[p.pid()] += 1; ++ntotal; } if(ntotal==2 && nCount[130]==1 && nCount[310]==1) _nKSKL->fill(); } /// Normalise histograms etc., after the run void finalize() { double sigma = _nKSKL->val()*crossSection()/ sumOfWeights() /picobarn; double error = _nKSKL->err()*crossSection()/ sumOfWeights() /picobarn; Scatter2D temphisto(refData(1, 1, 1)); Scatter2DPtr mult; book(mult, 1, 1, 1); for (size_t b = 0; b < temphisto.numPoints(); b++) { const double x = temphisto.point(b).x(); pair ex = temphisto.point(b).xErrs(); pair ex2 = ex; if(ex2.first ==0.) ex2. first=0.0001; if(ex2.second==0.) ex2.second=0.0001; if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) { mult->addPoint(x, sigma, ex, make_pair(error,error)); } else { mult->addPoint(x, 0., ex, make_pair(0.,.0)); } } } ///@} /// @name Histograms ///@{ CounterPtr _nKSKL; ///@} }; DECLARE_RIVET_PLUGIN(BABAR_2020_I1769654); }