1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief D meson production at 13 TeV
 9  class CMS_2021_I1876550 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2021_I1876550);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // projections
22      declare(UnstableParticles(), "UFS");
23      // histograms
24      for (unsigned int ix=0; ix<3; ++ix) {
25        book(_h_pT [ix], 1, 1, 1+ix);
26        book(_h_eta[ix], 2, 1, 1+ix);
27      }
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      // Final state of unstable particles to get particle spectra
34      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
35      for (const Particle& p : ufs.particles(Cuts::abspid==411 or Cuts::abspid==421 or Cuts::abspid==413)) {
36        // no mixing and |y|<2.1
37        if (p.children().size()==1) continue;
38        const double eta = p.abseta();
39        const double pT=p.perp();
40        if (eta>2.1 || pT<4. || pT>100.) continue;
41        if (p.fromBottom()) continue;
42        unsigned int imeson=0;
43        if      (p.abspid()==421) imeson=1;
44        else if (p.abspid()==411) imeson=2;
45        _h_pT[imeson]->fill(pT);
46        _h_eta[imeson]->fill(eta);
47      }
48    }
49
50
51    /// Normalise histograms etc., after the run
52    void finalize() {
53      const double factor = crossSection()/microbarn/sumOfWeights();
54      for (unsigned int ix=0; ix<3; ++ix) {
55        scale(_h_pT[ix], factor);
56        scale(_h_eta[ix], 0.5*factor);
57      }
58    }
59
60    /// @}
61
62
63    /// @name Histograms
64    /// @{
65    Histo1DPtr _h_pT[3], _h_eta[3];
66    /// @}
67
68
69  };
70
71
72  RIVET_DECLARE_PLUGIN(CMS_2021_I1876550);
73
74}