Rivet analyses referenceCMS_2018_I1643640Azimuthal correlations for inclusive 2-jet, 3-jet, and 4-jet events in pp collisions at $\sqrt{s}$ = 13 TeVExperiment: CMS (LHC) Inspire ID: 1643640 Status: VALIDATED Authors:
Beam energies: (6500.0, 6500.0) GeV Run details:
Azimuthal correlations between the two jets with the largest transverse momenta $p_T$ in inclusive 2-, 3-, and 4-jet events are presented for several regions of the leading jet $p_T$ up to 4 TeV. For 3- and 4-jet scenarios, measurements of the minimum azimuthal angles between any two of the three or four leading $p_T$ jets are also presented. The analysis is based on data from proton-proton collisions collected by the CMS Collaboration at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. Calculations based on leading-order matrix elements supplemented with parton showering and hadronization do not fully describe the data, so next-to-leading-order calculations matched with parton shower and hadronization models are needed to better describe the measured distributions. Furthermore, we show that azimuthal jet correlations are sensitive to details of the parton showering, hadronization, and multiparton interactions. A next-to-leading-order calculation matched with parton showers in the MC\@NLO method, as implemented in HERWIG 7, gives a better overall description of the measurements than the POWHEG method. Source code: CMS_2018_I1643640.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 /// CMS Azimuthal corellations at 13 TeV
10 class CMS_2018_I1643640 : public Analysis {
11 public:
12
13 RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2018_I1643640);
14
15 void init() {
16 FinalState fs;
17 FastJets akt(fs, JetAlg::ANTIKT, 0.4);
18 declare(akt, "antikT");
19
20 const vector<double> edges_2J{200., 300., 400., 500., 600., 700., 800., 1000., 1200., 7000.};
21 const vector<double> edges{200., 300., 400., 500., 600., 700., 800., 1000., 7000.};
22 book(_h_deltaPhi_2J_phi12, edges_2J);
23 book(_h_deltaPhi_3J_phi12, edges);
24 book(_h_deltaPhi_4J_phi12, edges);
25 book(_h_deltaPhi_3J_phimin2J, edges);
26 book(_h_deltaPhi_4J_phimin2J, edges);
27 for (size_t i=1; i<_h_deltaPhi_2J_phi12->numBins()+1; ++i) {
28 book(_h_deltaPhi_2J_phi12->bin(i), i, 1, 1);
29 if (i==9) continue;
30 book(_h_deltaPhi_3J_phi12->bin(i), 9+i, 1, 1);
31 book(_h_deltaPhi_4J_phi12->bin(i), 17+i, 1, 1);
32 book(_h_deltaPhi_3J_phimin2J->bin(i), 25+i, 1, 1);
33 book(_h_deltaPhi_4J_phimin2J->bin(i), 33+i, 1, 1);
34 }
35 }
36
37
38 void analyze(const Event & event) {
39 const Jets& jets = apply<JetFinder>(event, "antikT").jetsByPt();
40
41 // 2 jet case and Delta_phi12
42 if( jets.size() >= 2 ) {
43 if ( (jets[0].pT() >= 200.*GeV) && (jets[1].pT() >= 100.*GeV) ) {
44 if ( (fabs(jets[0].rap()) <= 2.5) && (fabs(jets[1].rap()) <= 2.5) ) {
45 double dphi = deltaPhi(jets[0].phi(), jets[1].phi());
46 _h_deltaPhi_2J_phi12->fill(jets[0].pT(), dphi);
47 }
48 }
49 }
50
51 // 3 jet case and Delta_phi12
52 if ( jets.size() >= 3 ) {
53 if ( (jets[0].pT() >= 200.*GeV) && (jets[1].pT() >= 100.*GeV) && (jets[2].pT() >= 100.*GeV) ) {
54 if ( (fabs(jets[0].rap()) <= 2.5) && (fabs(jets[1].rap()) <= 2.5) && (fabs(jets[2].rap()) <= 2.5)) {
55 double dphi = deltaPhi(jets[0].phi(), jets[1].phi());
56 _h_deltaPhi_3J_phi12->fill(jets[0].pT(), dphi);
57 }
58 }
59 }
60
61 // 4 jet case and Delta_phi12
62 if ( jets.size() >= 4 ) {
63 if ( (jets[0].pT() >= 200.*GeV) && (jets[1].pT() >= 100.*GeV) && (jets[2].pT() >= 100.*GeV) && (jets[3].pT() >= 100.*GeV)) {
64 if ( (fabs(jets[0].rap()) <= 2.5) && (fabs(jets[1].rap()) <= 2.5) && (fabs(jets[2].rap()) <= 2.5) && (fabs(jets[3].rap()) <= 2.5)) {
65 double dphi = deltaPhi(jets[0].phi(), jets[1].phi());
66 _h_deltaPhi_4J_phi12->fill(jets[0].pT(), dphi);
67 }
68 }
69 }
70
71 // 3 jet case and Delta_Phi_min2j
72 if ( jets.size() >= 3 ) {
73 if ( (jets[0].pT() >= 200.*GeV) && (jets[1].pT() >= 100.*GeV) && (jets[2].pT() >= 100.*GeV) ) {
74 if ( (fabs(jets[0].rap()) <= 2.5) && (fabs(jets[1].rap()) <= 2.5) && (fabs(jets[2].rap()) <= 2.5)) {
75 double dphi01 = deltaPhi(jets[0].phi(), jets[1].phi());
76 if (dphi01 >= PI/2. ){
77 double dphi02 = deltaPhi(jets[0].phi(), jets[2].phi());
78 double dphi12 = deltaPhi(jets[1].phi(), jets[2].phi());
79 // evaluate DPhi2Jmin
80 vector<double> Dphis2J{dphi01,dphi02,dphi12};
81 double DPhi2Jmin = min(Dphis2J);
82 // double Dphis2J[3] = {dphi01,dphi02,dphi12};
83 // double DPhi2Jmin = Dphis2J[0];
84 // for (int gg=1; gg<3; ++gg) { if (DPhi2Jmin>Dphis2J[gg]) DPhi2Jmin = Dphis2J[gg]; }
85 _h_deltaPhi_3J_phimin2J->fill(jets[0].pT(), DPhi2Jmin);
86 }
87 }
88 }
89 }
90
91 // 4 jet case and Delta_Phi_min2j
92 if ( jets.size() >= 4 ) {
93 if ( (jets[0].pT() >= 200.*GeV) && (jets[1].pT() >= 100.*GeV) && (jets[2].pT() >= 100.*GeV) && (jets[3].pT() >= 100.*GeV)) {
94 if ( (fabs(jets[0].rap()) <= 2.5) && (fabs(jets[1].rap()) <= 2.5) && (fabs(jets[2].rap()) <= 2.5) && (fabs(jets[3].rap()) <= 2.5)) {
95 double dphi01 = deltaPhi(jets[0].phi(), jets[1].phi());
96 if (dphi01 >= PI/2.) {
97 double dphi02 = deltaPhi(jets[0].phi(), jets[2].phi());
98 double dphi03 = deltaPhi(jets[0].phi(), jets[3].phi());
99 double dphi12 = deltaPhi(jets[1].phi(), jets[2].phi());
100 double dphi13 = deltaPhi(jets[1].phi(), jets[3].phi());
101 double dphi23 = deltaPhi(jets[2].phi(), jets[3].phi());
102 /// evaluate DPhi2Jmin
103 // double Dphis2J[6]={dphi01,dphi02,dphi03,dphi12,dphi13,dphi23};
104 // double DPhi2Jmin=Dphis2J[0];
105 // for(int gg=1; gg<6; ++gg){ if(DPhi2Jmin>Dphis2J[gg]){DPhi2Jmin=Dphis2J[gg];} }
106 vector<double> Dphis2J{dphi01,dphi02,dphi03,dphi12,dphi13,dphi23};
107 double DPhi2Jmin = min(Dphis2J);
108 _h_deltaPhi_4J_phimin2J->fill(jets[0].pT(), DPhi2Jmin);
109 }
110 }
111 }
112 }
113 } // end analyze
114
115
116 void finalize() {
117 normalize(_h_deltaPhi_2J_phi12);
118 normalize(_h_deltaPhi_3J_phi12);
119 normalize(_h_deltaPhi_4J_phi12);
120 normalize(_h_deltaPhi_3J_phimin2J);
121 normalize(_h_deltaPhi_4J_phimin2J);
122 }
123
124
125 private:
126
127 Histo1DGroupPtr _h_deltaPhi_2J_phi12;
128 Histo1DGroupPtr _h_deltaPhi_3J_phi12;
129 Histo1DGroupPtr _h_deltaPhi_4J_phi12;
130 Histo1DGroupPtr _h_deltaPhi_3J_phimin2J;
131 Histo1DGroupPtr _h_deltaPhi_4J_phimin2J;
132
133 };
134
135
136 RIVET_DECLARE_PLUGIN(CMS_2018_I1643640);
137
138}
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