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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/TauFinder.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
namespace Rivet {
/// @brief MC validation analysis for tau decays involving photons
class MC_TAUS_PHOTONS : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(MC_TAUS_PHOTONS);
/// Book projections and histograms
void init() {
TauFinder taus(TauFinder::DecayMode::ANY, Cuts::pT > 500*MeV);
declare(taus, "Taus");
IdentifiedFinalState photons(Cuts::pT > 500*MeV, PID::PHOTON);
declare(photons, "Photons");
book(_nPhotonsEl, "nPhotonsEl", 20, 0, 20);
book(_nPhotonsMu, "nPhotonsMu", 20, 0, 20);
book(_nPhotonsHad, "nPhotonsHad", 20, 0, 20);
book(_tauMassEl, "tauMassEl", 50, 0, 5);
book(_tauMassMu, "tauMassMu", 50, 0, 5);
book(_tauMassHad, "tauMassHad", 50, 0, 5);
book(_pFracPhotonsEl, "pFracPhotonsEl", 50, 0, 2);
book(_pFracPhotonsMu, "pFracPhotonsMu", 50, 0, 2);
book(_pFracPhotonsHad, "pFracPhotonsHad", 50, 0, 2);
book(_logPFracPhotonsEl, "logPFracPhotonsEl", 50, -5, 0);
book(_logPFracPhotonsMu, "logPFracPhotonsMu", 50, -5, 0);
book(_logPFracPhotonsHad, "logPFracPhotonsHad", 50, -5, 0);
book(_logPFracNotPhotonsEl, "logPFracNotPhotonsEl", 50, -5, 0);
book(_logPFracNotPhotonsMu, "logPFracNotPhotonsMu", 50, -5, 0);
book(_logPFracNotPhotonsHad, "logPFracNotPhotonsHad", 50, -5, 0);
book(_restFramePhotonsEnergyEl, "RestFramePhotonsEnergyEl", 50, 0, 3);
book(_restFramePhotonsEnergyMu, "RestFramePhotonsEnergyMu", 50, 0, 3);
book(_restFramePhotonsEnergyHad, "RestFramePhotonsEnergyHad", 50, 0, 3);
return;
}
/// Per-event analysis
void analyze(const Event& event) {
const Particles taus = apply<TauFinder>(event, "Taus").particlesByPt();
const Particles photons = apply<IdentifiedFinalState>(event, "Photons").particlesByPt();
for (const auto& tau : taus) {
Particles descendants = tau.stableDescendants();
bool hasHad = false, hasEl = false, hasMu = false;
for (const auto& descendant : descendants) {
if (isHadron(descendant)) {
hasHad = true;
} else if (abs(descendant.pid()) == PID::ELECTRON) {
hasEl = true;
} else if (abs(descendant.pid()) == PID::MUON) {
hasMu = true;
}
continue;
}
// decaymode: hadronic = 0, electron = 1, muon = 2
int decaymode = -1;
if (hasHad) decaymode = 0;
else if (hasEl) decaymode = 1;
else if (hasMu) decaymode = 2;
assert(decaymode >= 0);
FourMomentum taumom;
FourMomentum photonmom;
int nphotons = 0;
for (const auto& descendant : descendants) {
if (descendant.pid() == PID::PHOTON) {
photonmom += descendant.mom();
nphotons++;
}
taumom += descendant.mom();
continue;
}
LorentzTransform boost =
LorentzTransform::mkFrameTransformFromBeta(taumom.betaVec());
float taumass = taumom.mass();
float photonfrac = photonmom.p() / tau.p();
if (photonfrac >= 1.0)
photonfrac = 1.0 - 1e-6;
if (decaymode == 0) {
_nPhotonsHad->fill(nphotons);
_tauMassHad->fill(taumass / GeV);
_pFracPhotonsHad->fill(photonfrac);
_logPFracPhotonsHad->fill(log(photonfrac));
_logPFracNotPhotonsHad->fill(log(1.0 - photonfrac));
_restFramePhotonsEnergyHad->fill(boost(photonmom).E() / GeV);
} else if (decaymode == 1) {
_nPhotonsEl->fill(nphotons);
_tauMassEl->fill(taumass / GeV);
_pFracPhotonsEl->fill(photonfrac);
_logPFracPhotonsEl->fill(log(photonfrac));
_logPFracNotPhotonsEl->fill(log(1.0 - photonfrac));
_restFramePhotonsEnergyEl->fill(boost(photonmom).E() / GeV);
} else if (decaymode == 2) {
_nPhotonsMu->fill(nphotons);
_tauMassMu->fill(taumass / GeV);
_pFracPhotonsMu->fill(photonfrac);
_logPFracPhotonsMu->fill(log(photonfrac));
_logPFracNotPhotonsMu->fill(log(1.0 - photonfrac));
_restFramePhotonsEnergyMu->fill(boost(photonmom).E() / GeV);
}
continue;
}
return;
}
/// Normalisations etc.
void finalize() {
_nPhotonsEl->normalize();
_nPhotonsMu->normalize();
_nPhotonsHad->normalize();
_tauMassEl->normalize();
_tauMassMu->normalize();
_tauMassHad->normalize();
_pFracPhotonsEl->normalize();
_pFracPhotonsMu->normalize();
_pFracPhotonsHad->normalize();
_logPFracPhotonsEl->normalize();
_logPFracPhotonsMu->normalize();
_logPFracPhotonsHad->normalize();
_logPFracNotPhotonsEl->normalize();
_logPFracNotPhotonsMu->normalize();
_logPFracNotPhotonsHad->normalize();
_restFramePhotonsEnergyEl->normalize();
_restFramePhotonsEnergyMu->normalize();
_restFramePhotonsEnergyHad->normalize();
return;
}
private:
Histo1DPtr
_nPhotonsEl
, _nPhotonsMu
, _nPhotonsHad
, _tauMassEl
, _tauMassMu
, _tauMassHad
, _pFracPhotonsEl
, _pFracPhotonsMu
, _pFracPhotonsHad
, _logPFracPhotonsEl
, _logPFracPhotonsMu
, _logPFracPhotonsHad
, _logPFracNotPhotonsEl
, _logPFracNotPhotonsMu
, _logPFracNotPhotonsHad
, _restFramePhotonsEnergyEl
, _restFramePhotonsEnergyMu
, _restFramePhotonsEnergyHad
;
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(MC_TAUS_PHOTONS);
}
|