1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/ChargedFinalState.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief H1 charged particle photoproduction
10  class H1_1998_I477556 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(H1_1998_I477556);
15
16    /// @name Analysis methods
17    //@{
18
19    // Book projections and histograms
20    void init() {
21
22      // Acceptance
23      const FinalState fs(Cuts::abseta < 1 && Cuts::pT > 2*GeV);
24      const ChargedFinalState cfs(fs);
25      declare(cfs, "CFS");
26
27      // Table 1, pT spectra
28      book(_h_ch_pT, 1, 1, 1);
29      // Table 2, eta distributions with different pT cuts.
30      book(_h_ch_eta[0], 2, 1, 1);
31      book(_h_ch_eta[1], 2, 1, 2);
32    }
33
34    // Do the analysis
35    void analyze(const Event& event) {
36
37      // Loop over charged particles and fill histograms.
38      const Particles& particles = apply<FinalState>(event, "CFS").particles();
39      for (const Particle& p : particles) {
40
41        // Cross section for dsigma/dpt^2deta but as a function of pT.
42        // Use the conversion factor as a weight.
43        _h_ch_pT->fill(p.pt()/GeV, 1.0 / (2*p.pt()/GeV));
44        _h_ch_eta[0]->fill(p.eta());
45        if (p.pt() > 3. * GeV) _h_ch_eta[1]->fill(p.eta());
46      }
47    }
48
49    // Finalize
50    void finalize() {
51      const double sf = crossSection()/nanobarn/sumOfWeights();
52      // For d^2sigma/dpT^2deta scale with eta bin width.
53      scale(_h_ch_pT, 0.5 * sf);
54      scale(_h_ch_eta, sf);
55    }
56
57    //@}
58
59
60  private:
61
62    /// @name Histograms
63    //@{
64    Histo1DPtr _h_ch_pT, _h_ch_eta[2];
65    //@}
66
67  };
68
69  RIVET_DECLARE_PLUGIN(H1_1998_I477556);
70
71}