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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/VisibleFinalState.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
namespace Rivet {
/// @brief 0-lepton squark and gluino search
///
/// @author Chris Wymant
class ATLAS_2011_S9212183 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_S9212183);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// Projection to find the electrons
IdentifiedFinalState elecs(Cuts::abseta < 2.47 && Cuts::pT > 20*GeV);
elecs.acceptIdPair(PID::ELECTRON);
declare(elecs, "elecs");
// Projection to find the muons
IdentifiedFinalState muons(Cuts::abseta < 2.4 && Cuts::pT > 10*GeV);
muons.acceptIdPair(PID::MUON);
declare(muons, "muons");
// Jet finder
declare(FastJets(FinalState(), FastJets::ANTIKT, 0.4), "AntiKtJets04");
// All tracks (to do deltaR with leptons)
declare(ChargedFinalState(Cuts::abseta < 3.0), "cfs");
// Used for pTmiss (N.B. the real 'vfs' extends beyond 4.5 to |eta| = 4.9)
declare(VisibleFinalState(Cuts::abseta < 4.5), "vfs");
// Book histograms
book(_count_2j ,"count_2j", 1, 0., 1.);
book(_count_3j ,"count_3j", 1, 0., 1.);
book(_count_4j5 ,"count_4j5", 1, 0., 1.);
book(_count_4j10 ,"count_4j10", 1, 0., 1.);
book(_count_HM ,"count_HM", 1, 0., 1.);
book(_hist_meff_2j ,1, 1, 1);
book(_hist_meff_3j ,2, 1, 1);
book(_hist_meff_4j ,3, 1, 1);
book(_hist_meff_HM ,4, 1, 1);
book(_hist_eTmiss ,"Et_miss", 20, 0., 1000.);
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const double weight = 1.0;
Jets cand_jets;
const Jets jets = apply<FastJets>(event, "AntiKtJets04").jetsByPt(20.0*GeV);
for (const Jet& jet : jets) {
if ( fabs( jet.eta() ) < 4.9 ) {
cand_jets.push_back(jet);
}
}
const Particles cand_e = apply<IdentifiedFinalState>(event, "elecs").particlesByPt();
// Muon isolation not mentioned in hep-exp 1109.6572, unlike in 1102.5290,
// but assumed to still be applicable
Particles cand_mu;
const Particles chg_tracks = apply<ChargedFinalState>(event, "cfs").particles();
const Particles muons = apply<IdentifiedFinalState>(event, "muons").particlesByPt();
for (const Particle& mu : muons) {
double pTinCone = -mu.pT();
for (const Particle& track : chg_tracks) {
if ( deltaR(mu.momentum(),track.momentum()) <= 0.2 ) {
pTinCone += track.pT();
}
}
if ( pTinCone < 1.8*GeV ) cand_mu.push_back(mu);
}
// Resolve jet-lepton overlap for jets with |eta| < 2.8
Jets cand_jets_2;
for ( const Jet& jet : cand_jets ) {
if ( fabs( jet.eta() ) >= 2.8 ) {
cand_jets_2.push_back( jet );
} else {
bool away_from_e = true;
for ( const Particle & e : cand_e ) {
if ( deltaR(e.momentum(),jet.momentum()) <= 0.2 ) {
away_from_e = false;
break;
}
}
if ( away_from_e ) cand_jets_2.push_back( jet );
}
}
Particles recon_e, recon_mu;
for ( const Particle & e : cand_e ) {
bool away = true;
for ( const Jet& jet : cand_jets_2 ) {
if ( deltaR(e.momentum(),jet.momentum()) < 0.4 ) {
away = false;
break;
}
}
if ( away ) recon_e.push_back( e );
}
for ( const Particle & mu : cand_mu ) {
bool away = true;
for ( const Jet& jet : cand_jets_2 ) {
if ( deltaR(mu.momentum(),jet.momentum()) < 0.4 ) {
away = false;
break;
}
}
if ( away ) recon_mu.push_back( mu );
}
// pTmiss
// Based on all candidate electrons, muons and jets, plus everything else with |eta| < 4.5
// i.e. everything in our projection "vfs" plus the jets with |eta| > 4.5
Particles vfs_particles = apply<VisibleFinalState>(event, "vfs").particles();
FourMomentum pTmiss;
for ( const Particle & p : vfs_particles ) {
pTmiss -= p.momentum();
}
for ( const Jet& jet : cand_jets_2 ) {
if ( fabs( jet.eta() ) > 4.5 ) pTmiss -= jet.momentum();
}
double eTmiss = pTmiss.pT();
// Final jet filter
Jets recon_jets;
for ( const Jet& jet : cand_jets_2 ) {
if ( fabs( jet.eta() ) <= 2.8 ) recon_jets.push_back( jet );
}
// NB. It seems that jets with |eta| > 2.8 could have been thrown away at
// the start; we don't do so, in order to follow both the structure of
// the paper and the similar Rivet analysis ATLAS_2011_S8983313
// 'candidate' muons needed only 10 GeV, to cause a veto they need 20 GeV
Particles veto_mu;
for ( const Particle & mu : cand_mu ) {
if ( mu.pT() >= 20.0*GeV ) veto_mu.push_back(mu);
}
if ( ! ( veto_mu.empty() && recon_e.empty() ) ) {
MSG_DEBUG("Charged leptons left after selection");
vetoEvent;
}
if ( eTmiss <= 130 * GeV ) {
MSG_DEBUG("Not enough eTmiss: " << eTmiss << " < 130");
vetoEvent;
}
if ( recon_jets.empty() || recon_jets[0].pT() <= 130.0 * GeV ) {
MSG_DEBUG("No hard leading jet in " << recon_jets.size() << " jets");
vetoEvent;
}
// ==================== observables ====================
int Njets = 0;
double min_dPhi = 999.999;
double pTmiss_phi = pTmiss.phi();
for ( const Jet& jet : recon_jets ) {
if ( jet.pT() > 40 * GeV ) {
if ( Njets < 3 ) {
min_dPhi = min( min_dPhi, deltaPhi( pTmiss_phi, jet.phi() ) );
}
++Njets;
}
}
int NjetsHighMass = 0;
for ( const Jet& jet : recon_jets ) {
if ( jet.pT() > 80.0 * GeV ) {
++NjetsHighMass;
}
}
if ( Njets < 2 ) {
MSG_DEBUG("Only " << Njets << " >40 GeV jets left");
vetoEvent;
}
if ( min_dPhi <= 0.4 ) {
MSG_DEBUG("dPhi too small");
vetoEvent;
}
// m_eff
double m_eff_2j = eTmiss + recon_jets[0].pT() + recon_jets[1].pT();
double m_eff_3j = recon_jets.size() < 3 ? -999.0 : m_eff_2j + recon_jets[2].pT();
double m_eff_4j = recon_jets.size() < 4 ? -999.0 : m_eff_3j + recon_jets[3].pT();
double m_eff_HM = eTmiss;
for ( const Jet& jet : recon_jets ) {
if ( jet.pT() > 40.0 * GeV ) m_eff_HM += jet.pT();
}
double et_meff_2j = eTmiss / m_eff_2j;
double et_meff_3j = eTmiss / m_eff_3j;
double et_meff_4j = eTmiss / m_eff_4j;
double et_meff_HM = eTmiss / m_eff_HM;
// ==================== FILL ====================
MSG_DEBUG( "Trying to fill "
<< Njets << ' '
<< m_eff_2j << ' '
<< et_meff_2j << ' '
<< m_eff_3j << ' '
<< et_meff_3j << ' '
<< m_eff_4j << ' '
<< et_meff_4j << ' '
<< m_eff_HM << ' '
<< et_meff_HM );
_hist_eTmiss->fill(eTmiss, weight);
// 2j region
if ( et_meff_2j > 0.3 ) {
_hist_meff_2j->fill(m_eff_2j, weight);
if ( m_eff_2j > 1000 * GeV ) {
MSG_DEBUG("Hits 2j");
_count_2j->fill(0.5, weight);
}
}
// 3j region
if ( Njets >= 3 && et_meff_3j > 0.25 ) {
_hist_meff_3j->fill(m_eff_3j, weight);
if ( m_eff_3j > 1000 * GeV ) {
MSG_DEBUG("Hits 3j");
_count_3j->fill(0.5, weight);
}
}
// 4j5 & 4j10 regions
if ( Njets >= 4 && et_meff_4j > 0.25 ) {
_hist_meff_4j->fill(m_eff_4j, weight);
if ( m_eff_4j > 500 * GeV ) {
MSG_DEBUG("Hits 4j5");
_count_4j5->fill(0.5, weight);
}
if ( m_eff_4j > 1000 * GeV ) {
MSG_DEBUG("Hits 4j10");
_count_4j10->fill(0.5, weight);
}
}
// High mass region
if ( NjetsHighMass >= 4 && et_meff_HM > 0.2 ) {
_hist_meff_HM->fill(m_eff_HM, weight);
if ( m_eff_HM > 1100 * GeV ) {
MSG_DEBUG("Hits HM");
_count_HM->fill(0.5, weight);
}
}
}
void finalize() {
// Two, three and four jet channels have bin width = 100 (GeV)
// High mass channel has bin width = 150 (GeV)
// Integrated luminosity = 1040 (pb)
scale( _hist_meff_2j, 100. * 1040 * crossSection()/sumOfWeights() );
scale( _hist_meff_3j, 100. * 1040 * crossSection()/sumOfWeights() );
scale( _hist_meff_4j, 100. * 1040 * crossSection()/sumOfWeights() );
scale( _hist_meff_HM, 150. * 1040 * crossSection()/sumOfWeights() );
}
//@}
private:
Histo1DPtr _count_2j;
Histo1DPtr _count_3j;
Histo1DPtr _count_4j5;
Histo1DPtr _count_4j10;
Histo1DPtr _count_HM;
Histo1DPtr _hist_meff_2j;
Histo1DPtr _hist_meff_3j;
Histo1DPtr _hist_meff_4j;
Histo1DPtr _hist_meff_HM;
Histo1DPtr _hist_eTmiss;
};
RIVET_DECLARE_ALIASED_PLUGIN(ATLAS_2011_S9212183, ATLAS_2011_I930002);
}
|