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
| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief OPAL K0 fragmentation function paper
///
/// @author Peter Richardson
class OPAL_2000_S4418603 : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_2000_S4418603);
/// @name Analysis methods
/// @{
void init() {
declare(Beam(), "Beams");
declare(ChargedFinalState(), "FS");
declare(UnstableParticles(), "UFS");
book(_histXeK0 , 3, 1, 1);
}
void analyze(const Event& e) {
// First, veto on leptonic events by requiring at least 4 charged FS particles
const FinalState& fs = apply<FinalState>(e, "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>(e, "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>(e, "UFS");
for (const Particle& p : ufs.particles()) {
const int id = p.abspid();
if (id == PID::K0S || id == PID::K0L) {
double xE = p.E()/meanBeamMom;
_histXeK0->fill(xE);
}
}
}
/// Finalize
void finalize() {
scale(_histXeK0, 1./sumOfWeights());
}
/// @}
private:
/// Histogram
Histo1DPtr _histXeK0;
};
RIVET_DECLARE_ALIASED_PLUGIN(OPAL_2000_S4418603, OPAL_2000_I529898);
}
|