Rivet analyses referenceCMD2_2003_I601222Cross section for $e^+e^-\to K^0_SK^0_L$ at energies between 1.05 and 1.38 GeVExperiment: CMD2 (VEPP-2M) Inspire ID: 601222 Status: VALIDATED Authors:
Beam energies: ANY Run details:
1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4
5namespace Rivet {
6
7
8 /// @brief Add a short analysis description here
9 class CMD2_2003_I601222 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_2003_I601222);
14
15
16 /// @name Analysis methods
17 //@{
18
19 /// Book histograms and initialise projections before the run
20 void init() {
21
22 declare(FinalState(), "FS");
23 book(_nK0K0, "TMP/K0K0");
24
25 }
26
27
28 /// Perform the per-event analysis
29 void analyze(const Event& event) {
30
31 const FinalState& fs = apply<FinalState>(event, "FS");
32
33 map<long,int> nCount;
34 int ntotal(0);
35 for (const Particle& p : fs.particles()) {
36 nCount[p.pid()] += 1;
37 ++ntotal;
38 }
39 if(ntotal==2 &&
40 nCount[130]==1 && nCount[310]==1)
41 _nK0K0->fill();
42
43 }
44
45
46 /// Normalise histograms etc., after the run
47 void finalize() {
48
49 double sigma = _nK0K0->val();
50 double error = _nK0K0->err();
51 sigma *= crossSection()/ sumOfWeights() /nanobarn;
52 error *= crossSection()/ sumOfWeights() /nanobarn;
53 Scatter2D temphisto(refData(1, 1, 1));
54 Scatter2DPtr mult;
55 book(mult, 1, 1, 1);
56 for (size_t b = 0; b < temphisto.numPoints(); b++) {
57 const double x = temphisto.point(b).x();
58 pair<double,double> ex = temphisto.point(b).xErrs();
59 pair<double,double> ex2 = ex;
60 if(ex2.first ==0.) ex2. first=0.0001;
61 if(ex2.second==0.) ex2.second=0.0001;
62 if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
63 mult->addPoint(x, sigma, ex, make_pair(error,error));
64 }
65 else {
66 mult->addPoint(x, 0., ex, make_pair(0.,.0));
67 }
68 }
69 }
70
71 //@}
72
73
74 /// @name Histograms
75 //@{
76 CounterPtr _nK0K0;
77 //@}
78
79
80 };
81
82
83 // The hook for the plugin system
84 RIVET_DECLARE_PLUGIN(CMD2_2003_I601222);
85
86
87}
|