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
83
84
85
86
87
88
89
90
| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief OPAL strange baryon paper
/// @author Peter Richardson
class OPAL_1997_I421977 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_1997_I421977);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
declare(UnstableParticles(), "UFS");
// Book histograms
book(_h_plus, 1, 1, 1);
book(_h_minus, 2, 1, 1);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// First, veto on leptonic events by requiring at least 4 charged FS particles
const FinalState& fs = apply<FinalState>(event, "FS");
const size_t numParticles = fs.particles().size();
// Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
if (numParticles < 2) {
MSG_DEBUG("Failed leptonic event cut");
vetoEvent;
}
MSG_DEBUG("Passed leptonic event cut");
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double meanBeamMom = ( beams.first.p3().mod() +
beams.second.p3().mod() ) / 2.0;
MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
// Final state of unstable particles to get particle spectra
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for (const Particle& p : ufs.particles()) {
const int id = p.abspid();
double xE = p.E()/meanBeamMom;
if(id==3222) _h_plus ->fill(xE);
else if(id==3112) _h_minus->fill(xE);
}
}
/// Normalise histograms etc., after the run
void finalize() {
double fact=1./sumOfWeights();
scale(_h_plus , fact);
scale(_h_minus, fact);
}
//@}
/// @name Histograms
//@{
Histo1DPtr _h_plus,_h_minus;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(OPAL_1997_I421977);
}
|