Rivet analyses referenceATLAS_2011_S9128077Measurement of multi-jet cross sectionsExperiment: ATLAS (LHC) Inspire ID: 917599 Status: VALIDATED Authors:
Beam energies: (3500.0, 3500.0) GeV Run details:
Inclusive multi-jet production is studied using an integrated luminosity of 2.4 pb-1. Results on multi-jet cross sections are presented differential in pT of the four leading jets, HT. Additionally three-to-two jet fractions are presented differential in different observables. Jets are anti-$k_t$ with $R=0.4$ and $R=0.6$, $p_\perp>80(60)$ GeV and $|\eta|<2.8$. Source code: ATLAS_2011_S9128077.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/FastJets.hh"
5
6namespace Rivet {
7
8
9 /// Measurement of multi-jet cross sections
10 class ATLAS_2011_S9128077 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_S9128077);
15
16
17 /// @name Analysis methods
18 //@{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22
23 // Projections
24 const FinalState fs;
25 FastJets j4(fs, FastJets::ANTIKT, 0.4);
26 j4.useInvisibles();
27 declare(j4, "AntiKtJets04");
28 FastJets j6(fs, FastJets::ANTIKT, 0.6);
29 j6.useInvisibles();
30 declare(j6, "AntiKtJets06");
31
32 // Persistent histograms
33 book(_h_jet_multi_inclusive ,1, 1, 1);
34 book(_h_jet_multi_ratio, 2, 1, 1, true);
35 _h_jet_pT.resize(4);
36 book(_h_jet_pT[0] ,3, 1, 1);
37 book(_h_jet_pT[1] ,4, 1, 1);
38 book(_h_jet_pT[2] ,5, 1, 1);
39 book(_h_jet_pT[3] ,6, 1, 1);
40 book(_h_HT_2 ,7, 1, 1);
41 book(_h_HT_3 ,8, 1, 1);
42 book(_h_HT_4 ,9, 1, 1);
43 //
44 book(_h_pTlead_R06_60_ratio, 10, 1, 1);
45 book(_h_pTlead_R06_80_ratio, 11, 1, 1);
46 book(_h_pTlead_R06_110_ratio, 12, 1, 1);
47 book(_h_pTlead_R04_60_ratio, 13, 1, 1);
48 book(_h_pTlead_R04_80_ratio, 14, 1, 1);
49 book(_h_pTlead_R04_110_ratio, 15, 1, 1);
50 book(_h_HT2_R06_ratio, 16, 1, 1);
51 book(_h_HT2_R04_ratio, 17, 1, 1);
52
53 // Temporary histograms to be divided for the dsigma3/dsigma2 ratios
54 book(_h_tmp_pTlead_R06_60_2 , "_pTlead_R06_60_2", refData(10, 1, 1));
55 book(_h_tmp_pTlead_R06_80_2 , "_pTlead_R06_80_2", refData(11, 1, 1));
56 book(_h_tmp_pTlead_R06_110_2, "_pTlead_R06_110_2", refData(12, 1, 1));
57 book(_h_tmp_pTlead_R06_60_3 , "_pTlead_R06_60_3", refData(10, 1, 1));
58 book(_h_tmp_pTlead_R06_80_3 , "_pTlead_R06_80_3", refData(11, 1, 1));
59 book(_h_tmp_pTlead_R06_110_3, "_pTlead_R06_110_3", refData(12, 1, 1));
60 //
61 book(_h_tmp_pTlead_R04_60_2 , "_pTlead_R04_60_2", refData(13, 1, 1));
62 book(_h_tmp_pTlead_R04_80_2 , "_pTlead_R04_80_2", refData(14, 1, 1));
63 book(_h_tmp_pTlead_R04_110_2, "_pTlead_R04_110_2", refData(15, 1, 1));
64 book(_h_tmp_pTlead_R04_60_3 , "_pTlead_R04_60_3", refData(13, 1, 1));
65 book(_h_tmp_pTlead_R04_80_3 , "_pTlead_R04_80_3", refData(14, 1, 1));
66 book(_h_tmp_pTlead_R04_110_3, "_pTlead_R04_110_3", refData(15, 1, 1));
67 //
68 book(_h_tmp_HT2_R06_2, "_HT2_R06_2", refData(16, 1, 1));
69 book(_h_tmp_HT2_R06_3, "_HT2_R06_3", refData(16, 1, 1));
70 book(_h_tmp_HT2_R04_2, "_HT2_R04_2", refData(17, 1, 1));
71 book(_h_tmp_HT2_R04_3, "_HT2_R04_3", refData(17, 1, 1));
72 }
73
74
75 /// Perform the per-event analysis
76 void analyze(const Event& event) {
77 vector<FourMomentum> jets04;
78 for (const Jet& jet : apply<FastJets>(event, "AntiKtJets04").jetsByPt(60.0*GeV)) {
79 if (jet.abseta() < 2.8) {
80 jets04.push_back(jet.momentum());
81 }
82 }
83
84 if (jets04.size() > 1 && jets04[0].pT() > 80.0*GeV) {
85 for (size_t i = 2; i <= jets04.size(); ++i) {
86 _h_jet_multi_inclusive->fill(i);
87 }
88
89 double HT = 0.0;
90 for (size_t i = 0; i < jets04.size(); ++i) {
91 if (i < _h_jet_pT.size()) _h_jet_pT[i]->fill(jets04[i].pT());
92 HT += jets04[i].pT();
93 }
94
95 if (jets04.size() >= 2) _h_HT_2->fill(HT);
96 if (jets04.size() >= 3) _h_HT_3->fill(HT);
97 if (jets04.size() >= 4) _h_HT_4->fill(HT);
98
99 double pT1(jets04[0].pT()), pT2(jets04[1].pT());
100 double HT2 = pT1 + pT2;
101 if (jets04.size() >= 2) {
102 _h_tmp_HT2_R04_2->fill(HT2);
103 _h_tmp_pTlead_R04_60_2->fill(pT1);
104 if (pT2 > 80.0*GeV) _h_tmp_pTlead_R04_80_2->fill(pT1);
105 if (pT2 > 110.0*GeV) _h_tmp_pTlead_R04_110_2->fill(pT1);
106 }
107 if (jets04.size() >= 3) {
108 double pT3(jets04[2].pT());
109 _h_tmp_HT2_R04_3->fill(HT2);
110 _h_tmp_pTlead_R04_60_3->fill(pT1);
111 if (pT3 > 80.0*GeV) _h_tmp_pTlead_R04_80_3->fill(pT1);
112 if (pT3 > 110.0*GeV) _h_tmp_pTlead_R04_110_3->fill(pT1);
113 }
114 }
115
116 /// @todo It'd be better to avoid duplicating 95% of the code!
117 vector<FourMomentum> jets06;
118 for (const Jet& jet : apply<FastJets>(event, "AntiKtJets06").jetsByPt(60.0*GeV)) {
119 if (jet.abseta() < 2.8) {
120 jets06.push_back(jet.momentum());
121 }
122 }
123 if (jets06.size() > 1 && jets06[0].pT() > 80.0*GeV) {
124 double pT1(jets06[0].pT()), pT2(jets06[1].pT());
125 double HT2 = pT1 + pT2;
126 if (jets06.size() >= 2) {
127 _h_tmp_HT2_R06_2->fill(HT2);
128 _h_tmp_pTlead_R06_60_2->fill(pT1);
129 if (pT2 > 80.0*GeV) _h_tmp_pTlead_R06_80_2->fill(pT1);
130 if (pT2 > 110.0*GeV) _h_tmp_pTlead_R06_110_2->fill(pT1);
131 }
132 if (jets06.size() >= 3) {
133 double pT3(jets06[2].pT());
134 _h_tmp_HT2_R06_3->fill(HT2);
135 _h_tmp_pTlead_R06_60_3->fill(pT1);
136 if (pT3 > 80.0*GeV) _h_tmp_pTlead_R06_80_3->fill(pT1);
137 if (pT3 > 110.0*GeV) _h_tmp_pTlead_R06_110_3->fill(pT1);
138 }
139 }
140
141 }
142
143
144 /// Normalise histograms etc., after the run
145 void finalize() {
146
147 // Normalize std histos
148 scale(_h_jet_multi_inclusive, crossSectionPerEvent());
149 scale(_h_jet_pT[0], crossSectionPerEvent());
150 scale(_h_jet_pT[1], crossSectionPerEvent());
151 scale(_h_jet_pT[2], crossSectionPerEvent());
152 scale(_h_jet_pT[3], crossSectionPerEvent());
153 scale(_h_HT_2, crossSectionPerEvent());
154 scale(_h_HT_3, crossSectionPerEvent());
155 scale(_h_HT_4, crossSectionPerEvent());
156
157 scale(_h_tmp_pTlead_R06_60_2 , crossSectionPerEvent());
158 scale(_h_tmp_pTlead_R06_80_2 , crossSectionPerEvent());
159 scale(_h_tmp_pTlead_R06_110_2, crossSectionPerEvent());
160 scale(_h_tmp_pTlead_R06_60_3 , crossSectionPerEvent());
161 scale(_h_tmp_pTlead_R06_80_3 , crossSectionPerEvent());
162 scale(_h_tmp_pTlead_R06_110_3, crossSectionPerEvent());
163
164 scale(_h_tmp_pTlead_R04_60_2 , crossSectionPerEvent());
165 scale(_h_tmp_pTlead_R04_80_2 , crossSectionPerEvent());
166 scale(_h_tmp_pTlead_R04_110_2, crossSectionPerEvent());
167 scale(_h_tmp_pTlead_R04_60_3 , crossSectionPerEvent());
168 scale(_h_tmp_pTlead_R04_80_3 , crossSectionPerEvent());
169 scale(_h_tmp_pTlead_R04_110_3, crossSectionPerEvent());
170
171 scale(_h_tmp_HT2_R06_2, crossSectionPerEvent());
172 scale(_h_tmp_HT2_R06_3, crossSectionPerEvent());
173 scale(_h_tmp_HT2_R04_2, crossSectionPerEvent());
174 scale(_h_tmp_HT2_R04_3, crossSectionPerEvent());
175
176 // Fill inclusive jet multiplicity ratio
177 for (size_t b = 0; b < _h_jet_multi_ratio->numPoints(); ++b) {
178 if (_h_jet_multi_inclusive->bin(b).sumW() != 0) {
179 const double val = _h_jet_multi_inclusive->bin(b+1).sumW() / _h_jet_multi_inclusive->bin(b).sumW();
180 // @todo Shouldn't these be added in quadrature??
181 const double err = ( _h_jet_multi_inclusive->bin(b+1).relErr() + _h_jet_multi_inclusive->bin(b).relErr() ) * val;
182 _h_jet_multi_ratio->point(b).setY(val, err);
183 }
184 else {
185 _h_jet_multi_ratio->point(b).setY(0., 0.);
186 }
187 }
188
189 /// Create ratio histograms
190 divide(_h_tmp_pTlead_R06_60_3,_h_tmp_pTlead_R06_60_2, _h_pTlead_R06_60_ratio);
191 divide(_h_tmp_pTlead_R06_80_3,_h_tmp_pTlead_R06_80_2, _h_pTlead_R06_80_ratio);
192 divide(_h_tmp_pTlead_R06_110_3,_h_tmp_pTlead_R06_110_2, _h_pTlead_R06_110_ratio);
193 divide(_h_tmp_pTlead_R04_60_3,_h_tmp_pTlead_R04_60_2, _h_pTlead_R04_60_ratio);
194 divide(_h_tmp_pTlead_R04_80_3,_h_tmp_pTlead_R04_80_2, _h_pTlead_R04_80_ratio);
195 divide(_h_tmp_pTlead_R04_110_3,_h_tmp_pTlead_R04_110_2, _h_pTlead_R04_110_ratio);
196 divide(_h_tmp_HT2_R06_3,_h_tmp_HT2_R06_2, _h_HT2_R06_ratio);
197 divide(_h_tmp_HT2_R04_3,_h_tmp_HT2_R04_2, _h_HT2_R04_ratio);
198 }
199
200 //@}
201
202
203 private:
204
205 /// @name Histograms
206 //@{
207 Histo1DPtr _h_jet_multi_inclusive;
208 Scatter2DPtr _h_jet_multi_ratio;
209 vector<Histo1DPtr> _h_jet_pT;
210 Histo1DPtr _h_HT_2;
211 Histo1DPtr _h_HT_3;
212 Histo1DPtr _h_HT_4;
213 //@}
214
215 /// @name Ratio histograms
216 //@{
217 Scatter2DPtr _h_pTlead_R06_60_ratio, _h_pTlead_R06_80_ratio, _h_pTlead_R06_110_ratio;
218 Scatter2DPtr _h_pTlead_R04_60_ratio, _h_pTlead_R04_80_ratio, _h_pTlead_R04_110_ratio;
219 Scatter2DPtr _h_HT2_R06_ratio, _h_HT2_R04_ratio;
220 //@}
221
222 /// @name Temporary histograms to be divided for the dsigma3/dsigma2 ratios
223 //@{
224 Histo1DPtr _h_tmp_pTlead_R06_60_2, _h_tmp_pTlead_R06_80_2, _h_tmp_pTlead_R06_110_2;
225 Histo1DPtr _h_tmp_pTlead_R06_60_3, _h_tmp_pTlead_R06_80_3, _h_tmp_pTlead_R06_110_3;
226 Histo1DPtr _h_tmp_pTlead_R04_60_2, _h_tmp_pTlead_R04_80_2, _h_tmp_pTlead_R04_110_2;
227 Histo1DPtr _h_tmp_pTlead_R04_60_3, _h_tmp_pTlead_R04_80_3, _h_tmp_pTlead_R04_110_3;
228 Histo1DPtr _h_tmp_HT2_R06_2, _h_tmp_HT2_R06_3, _h_tmp_HT2_R04_2, _h_tmp_HT2_R04_3;
229 //@}
230
231 };
232
233
234
235 RIVET_DECLARE_ALIASED_PLUGIN(ATLAS_2011_S9128077, ATLAS_2011_I917599);
236
237
238}
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