Rivet analyses referenceD0_1996_I399364Topological distributions of inclusive three- and four-jet eventsExperiment: D0 (Tevatron Run 1) Inspire ID: 399364 Status: VALIDATED Authors:
Beam energies: (900.0, 900.0) GeV Run details:
The global topologies of inclusive three- and four-jet events produced in pbar p interactions are described. The three- and four-jet events are selected from data recorded by the D0 detector at the Fermilab Tevatron Collider operating at a center-of-mass energy of $\sqrt{s}$=1800 GeV. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well. The parton-shower Monte Carlo generators provide a less satisfactory description of the topologies of the three- and four-jet events. Source code: D0_1996_I399364.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/FastJets.hh"
5#include "Rivet/Math/LorentzTrans.hh"
6
7namespace Rivet {
8
9
10 /// D0 topological distributions of 3- and 4-jet events.
11 class D0_1996_I399364 : public Analysis {
12 public:
13
14 RIVET_DEFAULT_ANALYSIS_CTOR(D0_1996_I399364);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms
21 void init() {
22 const FinalState fs;
23
24 /// @todo Use correct jet algorithm --- tried FJ3 D0RunICone but does
25 // not look as good as the Run2 cone alg used here
26 declare(FastJets(fs, JetAlg::D0ILCONE, 0.7), "ConeJets");
27
28 book(_h_3j_x3 ,1, 1, 1);
29 book(_h_3j_x5 ,2, 1, 1);
30 book(_h_3j_costheta3 ,3, 1, 1);
31 book(_h_3j_psi ,4, 1, 1);
32 book(_h_3j_mu34 ,5, 1, 1);
33 book(_h_3j_mu35 ,6, 1, 1);
34 book(_h_3j_mu45 ,7, 1, 1);
35
36 book(_h_4j_x3 ,8, 1, 1);
37 book(_h_4j_x4 ,9, 1, 1);
38 book(_h_4j_x5 ,10, 1, 1);
39 book(_h_4j_x6 ,11, 1, 1);
40 book(_h_4j_costheta3 ,12, 1, 1);
41 book(_h_4j_costheta4 ,13, 1, 1);
42 book(_h_4j_costheta5 ,14, 1, 1);
43 book(_h_4j_costheta6 ,15, 1, 1);
44 book(_h_4j_cosomega34 ,16, 1, 1);
45 book(_h_4j_cosomega35 ,17, 1, 1);
46 book(_h_4j_cosomega36 ,18, 1, 1);
47 book(_h_4j_cosomega45 ,19, 1, 1);
48 book(_h_4j_cosomega46 ,20, 1, 1);
49 book(_h_4j_cosomega56 ,21, 1, 1);
50 book(_h_4j_mu34 ,22, 1, 1);
51 book(_h_4j_mu35 ,23, 1, 1);
52 book(_h_4j_mu36 ,24, 1, 1);
53 book(_h_4j_mu45 ,25, 1, 1);
54 book(_h_4j_mu46 ,26, 1, 1);
55 book(_h_4j_mu56 ,27, 1, 1);
56 book(_h_4j_theta_BZ ,28, 1, 1);
57 book(_h_4j_costheta_NR ,29, 1, 1);
58
59 }
60
61
62 void analyze(const Event& event) {
63 Jets jets_in = apply<FastJets>(event, "ConeJets")
64 .jets(Cuts::Et > 20*GeV && Cuts::abseta < 3, cmpMomByEt);
65
66 Jets jets_isolated;
67 for (size_t i = 0; i < jets_in.size(); ++i) {
68 bool isolated = true;
69 for (size_t j = 0; j < jets_in.size(); ++j) {
70 if (i != j && deltaR(jets_in[i], jets_in[j]) < 1.4) {
71 isolated = false;
72 break;
73 }
74 }
75 if (isolated) jets_isolated.push_back(jets_in[i]);
76 }
77
78 if (jets_isolated.empty() || jets_isolated[0].Et() < 60.0*GeV) vetoEvent;
79
80 if (jets_isolated.size() > 2) _threeJetAnalysis(jets_isolated);
81 if (jets_isolated.size() > 3) _fourJetAnalysis(jets_isolated);
82 }
83
84
85 void finalize() {
86 normalize(_h_3j_x3);
87 normalize(_h_3j_x5);
88 normalize(_h_3j_costheta3);
89 normalize(_h_3j_psi);
90 normalize(_h_3j_mu34);
91 normalize(_h_3j_mu35);
92 normalize(_h_3j_mu45);
93 normalize(_h_4j_x3);
94 normalize(_h_4j_x4);
95 normalize(_h_4j_x5);
96 normalize(_h_4j_x6);
97 normalize(_h_4j_costheta3);
98 normalize(_h_4j_costheta4);
99 normalize(_h_4j_costheta5);
100 normalize(_h_4j_costheta6);
101 normalize(_h_4j_cosomega34);
102 normalize(_h_4j_cosomega35);
103 normalize(_h_4j_cosomega36);
104 normalize(_h_4j_cosomega45);
105 normalize(_h_4j_cosomega46);
106 normalize(_h_4j_cosomega56);
107 normalize(_h_4j_mu34);
108 normalize(_h_4j_mu35);
109 normalize(_h_4j_mu36);
110 normalize(_h_4j_mu45);
111 normalize(_h_4j_mu46);
112 normalize(_h_4j_mu56);
113 normalize(_h_4j_theta_BZ);
114 normalize(_h_4j_costheta_NR);
115 }
116
117 /// @}
118
119
120 private:
121
122 /// @name Helper functions
123 /// @{
124
125 void _threeJetAnalysis(const Jets& jets) {
126 // >=3 jet events
127 FourMomentum jjj(jets[0].mom() + jets[1].mom() + jets[2].mom());
128 const double sqrts = _safeMass(jjj);
129 if (sqrts<200*GeV) return;
130
131 const LorentzTransform cms_boost = LorentzTransform::mkFrameTransformFromBeta(jjj.betaVec());
132 vector<FourMomentum> jets_boosted;
133 for (Jet jet : jets) {
134 jets_boosted.push_back(cms_boost.transform(jet.mom()));
135 }
136 isortBy(jets_boosted, cmpMomByE);
137 FourMomentum p3(jets_boosted[0]);
138 FourMomentum p4(jets_boosted[1]);
139 FourMomentum p5(jets_boosted[2]);
140
141 Vector3 beam1(0.0, 0.0, 1.0);
142 Vector3 p1xp3 = beam1.cross(p3.p3());
143 Vector3 p4xp5 = p4.p3().cross(p5.p3());
144 const double cospsi = p1xp3.dot(p4xp5)/p1xp3.mod()/p4xp5.mod();
145
146 _h_3j_x3->fill(2.0*p3.E()/sqrts);
147 _h_3j_x5->fill(2.0*p5.E()/sqrts);
148 _h_3j_costheta3->fill(fabs(cos(p3.theta())));
149 _h_3j_psi->fill(acos(cospsi)/degree);
150 _h_3j_mu34->fill(_safeMass(FourMomentum(p3+p4))/sqrts);
151 _h_3j_mu35->fill(_safeMass(FourMomentum(p3+p5))/sqrts);
152 _h_3j_mu45->fill(_safeMass(FourMomentum(p4+p5))/sqrts);
153 }
154
155
156 void _fourJetAnalysis(const Jets& jets) {
157 // >=4 jet events
158 FourMomentum jjjj(jets[0].momentum() + jets[1].momentum() + jets[2].momentum()+ jets[3].momentum());
159 const double sqrts = _safeMass(jjjj);
160 if (sqrts < 200*GeV) return;
161
162 const LorentzTransform cms_boost = LorentzTransform::mkFrameTransformFromBeta(jjjj.betaVec());
163 vector<FourMomentum> jets_boosted;
164 for (Jet jet : jets) {
165 jets_boosted.push_back(cms_boost.transform(jet.momentum()));
166 }
167 isortBy(jets_boosted, cmpMomByE);
168 FourMomentum p3(jets_boosted[0]);
169 FourMomentum p4(jets_boosted[1]);
170 FourMomentum p5(jets_boosted[2]);
171 FourMomentum p6(jets_boosted[3]);
172
173 Vector3 p3xp4 = p3.p3().cross(p4.p3());
174 Vector3 p5xp6 = p5.p3().cross(p6.p3());
175 const double costheta_BZ = p3xp4.dot(p5xp6)/p3xp4.mod()/p5xp6.mod();
176 const double costheta_NR = (p3.p3()-p4.p3()).dot(p5.p3()-p6.p3())/
177 (p3.p3()-p4.p3()).mod()/(p5.p3()-p6.p3()).mod();
178
179 _h_4j_x3->fill(2.0*p3.E()/sqrts);
180 _h_4j_x4->fill(2.0*p4.E()/sqrts);
181 _h_4j_x5->fill(2.0*p5.E()/sqrts);
182 _h_4j_x6->fill(2.0*p6.E()/sqrts);
183 _h_4j_costheta3->fill(fabs(cos(p3.theta())));
184 _h_4j_costheta4->fill(fabs(cos(p4.theta())));
185 _h_4j_costheta5->fill(fabs(cos(p5.theta())));
186 _h_4j_costheta6->fill(fabs(cos(p6.theta())));
187 _h_4j_cosomega34->fill(cos(p3.angle(p4)));
188 _h_4j_cosomega35->fill(cos(p3.angle(p5)));
189 _h_4j_cosomega36->fill(cos(p3.angle(p6)));
190 _h_4j_cosomega45->fill(cos(p4.angle(p5)));
191 _h_4j_cosomega46->fill(cos(p4.angle(p6)));
192 _h_4j_cosomega56->fill(cos(p5.angle(p6)));
193 _h_4j_mu34->fill(_safeMass(FourMomentum(p3+p4))/sqrts);
194 _h_4j_mu35->fill(_safeMass(FourMomentum(p3+p5))/sqrts);
195 _h_4j_mu36->fill(_safeMass(FourMomentum(p3+p6))/sqrts);
196 _h_4j_mu45->fill(_safeMass(FourMomentum(p4+p5))/sqrts);
197 _h_4j_mu46->fill(_safeMass(FourMomentum(p4+p6))/sqrts);
198 _h_4j_mu56->fill(_safeMass(FourMomentum(p5+p6))/sqrts);
199 _h_4j_theta_BZ->fill(acos(fabs(costheta_BZ))/degree);
200 _h_4j_costheta_NR->fill(fabs(costheta_NR));
201
202 }
203
204 double _safeMass(const FourMomentum& p) {
205 double mass2=p.mass2();
206 if (mass2>0.0) return sqrt(mass2);
207 else if (mass2<-1.0e-5) {
208 MSG_WARNING("m2 = " << m2 << ". Assuming m2=0.");
209 return 0.0;
210 }
211 else return 0.0;
212 }
213
214 /// @}
215
216
217 private:
218
219 /// @name Histograms
220 /// @{
221 Histo1DPtr _h_3j_x3;
222 Histo1DPtr _h_3j_x5;
223 Histo1DPtr _h_3j_costheta3;
224 Histo1DPtr _h_3j_psi;
225 Histo1DPtr _h_3j_mu34;
226 Histo1DPtr _h_3j_mu35;
227 Histo1DPtr _h_3j_mu45;
228
229 Histo1DPtr _h_4j_x3;
230 Histo1DPtr _h_4j_x4;
231 Histo1DPtr _h_4j_x5;
232 Histo1DPtr _h_4j_x6;
233 Histo1DPtr _h_4j_costheta3;
234 Histo1DPtr _h_4j_costheta4;
235 Histo1DPtr _h_4j_costheta5;
236 Histo1DPtr _h_4j_costheta6;
237 Histo1DPtr _h_4j_cosomega34;
238 Histo1DPtr _h_4j_cosomega35;
239 Histo1DPtr _h_4j_cosomega36;
240 Histo1DPtr _h_4j_cosomega45;
241 Histo1DPtr _h_4j_cosomega46;
242 Histo1DPtr _h_4j_cosomega56;
243 Histo1DPtr _h_4j_mu34;
244 Histo1DPtr _h_4j_mu35;
245 Histo1DPtr _h_4j_mu36;
246 Histo1DPtr _h_4j_mu45;
247 Histo1DPtr _h_4j_mu46;
248 Histo1DPtr _h_4j_mu56;
249 Histo1DPtr _h_4j_theta_BZ;
250 Histo1DPtr _h_4j_costheta_NR;
251 /// @}
252
253 };
254
255
256
257 RIVET_DECLARE_ALIASED_PLUGIN(D0_1996_I399364, D0_1996_S3214044);
258
259}
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