Rivet analyses referenceCELLO_1990_I283026Spectra for strange hadron production at $E_{\text{CMS}}=35$ GeVExperiment: CELLO (Petra) Inspire ID: 283026 Status: VALIDATED Authors:
Beam energies: (17.5, 17.5) GeV Run details:
Spectra for $K^0$, $K^{*+}$ and $\Lambda$ production in $e^+e^-$ collisions at a centre-of-mass energy of 35 GeV measured by the CELLO experiment at Petra. The data in HEPData only contains the centroids of the bins, not the bin edges which have therefore been inferred. Source code: CELLO_1990_I283026.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/ChargedFinalState.hh"
5#include "Rivet/Projections/UnstableParticles.hh"
6#include "Rivet/Projections/Beam.hh"
7
8namespace Rivet {
9
10
11 /// @brief Strange hadrons at 35GeV
12 class CELLO_1990_I283026 : public Analysis {
13 public:
14
15 /// Constructor
16 RIVET_DEFAULT_ANALYSIS_CTOR(CELLO_1990_I283026);
17
18
19 /// @name Analysis methods
20 /// @{
21
22 /// Book histograms and initialise projections before the run
23 void init() {
24
25 declare(Beam(), "Beams");
26 declare(ChargedFinalState(), "FS");
27 declare(UnstableParticles(), "UFS");
28
29 // Book histograms
30 book(_h["K0"], 1, 1, 1);
31 book(_h["Kstar"], 2, 1, 1);
32 book(_h["Lambda"], 3, 1, 1);
33
34 _axes["K0"] = YODA::Axis<double>({0.0315, 0.0365, 0.0535, 0.0745, 0.0955, 0.1165,
35 0.1415, 0.175, 0.2375, 0.282, 0.3775, 0.652});
36 _axes["Kstar"] = YODA::Axis<double>({0.055, 0.195, 0.335, 0.537, 0.883});
37 _axes["Lambda"] = YODA::Axis<double>({0.067, 0.085, 0.103, 0.131, 0.175, 0.269, 0.447, 0.723});
38
39 }
40
41
42 /// Perform the per-event analysis
43 void analyze(const Event& event) {
44
45 if (_edges.empty()) {
46 for (const auto& item : _h) {
47 _edges[item.first] = item.second->xEdges();
48 }
49 }
50
51 // First, veto on leptonic events by requiring at least 4 charged FS particles
52 const FinalState& fs = apply<FinalState>(event, "FS");
53 const size_t numParticles = fs.particles().size();
54
55 // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
56 if (numParticles < 2) {
57 MSG_DEBUG("Failed leptonic event cut");
58 vetoEvent;
59 }
60 MSG_DEBUG("Passed leptonic event cut");
61
62 // Get beams and average beam momentum
63 const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
64 const double meanBeamMom = 0.5*(beams.first.p3().mod() + beams.second.p3().mod());
65 MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
66
67 // Final state of unstable particles to get particle spectra
68 const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
69
70 for (const Particle& p : ufs.particles()) {
71 const int id = p.abspid();
72 if (id == PID::K0S || id == PID::K0L) {
73 discfill("K0", p.E()/meanBeamMom);
74 }
75 else if(abs(id)==323) {
76 discfill("Kstar", p.E()/meanBeamMom);
77 }
78 else if(abs(id)==3122) {
79 discfill("Lambda", p.E()/meanBeamMom);
80 }
81 }
82 }
83
84 void discfill(const string& name, const double value) {
85 string edge = "OTHER";
86 const size_t idx = _axes[name].index(value);
87 if (idx && idx <= _edges[name].size()) edge = _edges[name][idx-1];
88 _h[name]->fill(edge);
89 }
90
91
92 /// Normalise histograms etc., after the run
93 void finalize() {
94 scale(_h, 1./sumOfWeights());
95 for( auto & hist : _h) {
96 for(auto & b: hist.second->bins()) {
97 const size_t idx = b.index();
98 b.scaleW(1./_axes[hist.first].width(idx));
99 }
100 }
101 }
102
103 /// @}
104
105
106 /// @name Histograms
107 /// @{
108 map<string, BinnedHistoPtr<string>> _h;
109 map<string, YODA::Axis<double>> _axes;
110 map<string, vector<string>> _edges;
111 /// @}
112
113
114 };
115
116
117 RIVET_DECLARE_PLUGIN(CELLO_1990_I283026);
118
119
120}
|