Rivet analyses referenceD0_2009_S8349509Z+jets angular distributionsExperiment: D0 (Tevatron Run 2) Inspire ID: 826756 Status: VALIDATED Authors:
Beam energies: (980.0, 980.0) GeV Run details:
First measurements at a hadron collider of differential cross sections for $Z (\to \mu\mu)$+jet+X production in $\Delta\phi(Z, j)$, $|\Delta y(Z, j)|$ and $|y_\mathrm{boost}(Z, j)|$. Vector boson production in association with jets is an excellent probe of QCD and constitutes the main background to many small cross section processes, such as associated Higgs production. These measurements are crucial tests of the predictions of perturbative QCD and current event generators, which have varied success in describing the data. Using these measurements as inputs in tuning event generators will increase the experimental sensitivity to rare signals. Source code: D0_2009_S8349509.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/ZFinder.hh"
5#include "Rivet/Projections/FastJets.hh"
6
7namespace Rivet {
8
9
10 /// D0 Z+jets angular distributions
11 class D0_2009_S8349509 : public Analysis {
12 public:
13
14 RIVET_DEFAULT_ANALYSIS_CTOR(D0_2009_S8349509);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms
21 void init() {
22 Cut cut = Cuts::abseta < 1.7 && Cuts::pT > 15*GeV;
23 ZFinder zfinder(FinalState(), cut, PID::MUON, 65*GeV, 115*GeV, 0.2, ZFinder::ClusterPhotons::NONE, ZFinder::AddPhotons::YES);
24 declare(zfinder, "ZFinder");
25
26 FastJets conefinder(zfinder.remainingFinalState(), FastJets::D0ILCONE, 0.5);
27 declare(conefinder, "ConeFinder");
28
29 book(_h_dphi_jet_Z25 ,1, 1, 1);
30 book(_h_dphi_jet_Z45 ,2, 1, 1);
31
32 book(_h_dy_jet_Z25 ,3, 1, 1);
33 book(_h_dy_jet_Z45 ,4, 1, 1);
34
35 book(_h_yboost_jet_Z25 ,5, 1, 1);
36 book(_h_yboost_jet_Z45 ,6, 1, 1);
37
38 book(_h_dphi_jet_Z25_xs ,1, 1, 2);
39 book(_h_dphi_jet_Z45_xs ,2, 1, 2);
40
41 book(_h_dy_jet_Z25_xs ,3, 1, 2);
42 book(_h_dy_jet_Z45_xs ,4, 1, 2);
43
44 book(_h_yboost_jet_Z25_xs ,5, 1, 2);
45 book(_h_yboost_jet_Z45_xs ,6, 1, 2);
46
47 book(_inclusive_Z_sumofweights, "_inclusive_Z_sumofweights");
48 }
49
50
51 void analyze(const Event& event) {
52 const ZFinder& zfinder = apply<ZFinder>(event, "ZFinder");
53 if (zfinder.bosons().size() == 1) {
54 // count inclusive sum of weights for histogram normalisation
55 _inclusive_Z_sumofweights->fill();
56
57 const FourMomentum& zmom = zfinder.bosons()[0].momentum();
58 if (zmom.pT() < 25*GeV) vetoEvent;
59
60 Jets jets;
61 for (const Jet& j : apply<JetAlg>(event, "ConeFinder").jetsByPt(20*GeV)) {
62 if (j.abseta() < 2.8) {
63 jets.push_back(j);
64 break;
65 }
66 }
67
68 // Return if there are no jets:
69 if (jets.size() < 1) {
70 MSG_DEBUG("Skipping event " << numEvents() << " because no jets pass cuts ");
71 vetoEvent;
72 }
73
74 const FourMomentum& jetmom = jets[0].momentum();
75 const double yZ = zmom.rapidity();
76 const double yjet = jetmom.rapidity();
77 const double dphi = deltaPhi(zmom, jetmom);
78 const double dy = deltaRap(zmom, jetmom);
79 const double yboost = fabs(yZ+yjet)/2;
80
81 if (zmom.pT() > 25*GeV) {
82 _h_dphi_jet_Z25->fill(dphi);
83 _h_dy_jet_Z25->fill(dy);
84 _h_yboost_jet_Z25->fill(yboost);
85 _h_dphi_jet_Z25_xs->fill(dphi);
86 _h_dy_jet_Z25_xs->fill(dy);
87 _h_yboost_jet_Z25_xs->fill(yboost);
88 }
89 if (zmom.pT() > 45*GeV) {
90 _h_dphi_jet_Z45->fill(dphi);
91 _h_dy_jet_Z45->fill(dy);
92 _h_yboost_jet_Z45->fill(yboost);
93 _h_dphi_jet_Z45_xs->fill(dphi);
94 _h_dy_jet_Z45_xs->fill(dy);
95 _h_yboost_jet_Z45_xs->fill(yboost);
96 }
97 }
98
99 }
100
101
102 void finalize() {
103 if (_inclusive_Z_sumofweights->val() == 0) return;
104 scale(_h_dphi_jet_Z25, 1/ *_inclusive_Z_sumofweights);
105 scale(_h_dphi_jet_Z45, 1/ *_inclusive_Z_sumofweights);
106 scale(_h_dy_jet_Z25, 1/ *_inclusive_Z_sumofweights);
107 scale(_h_dy_jet_Z45, 1/ *_inclusive_Z_sumofweights);
108 scale(_h_yboost_jet_Z25, 1/ *_inclusive_Z_sumofweights);
109 scale(_h_yboost_jet_Z45, 1/ *_inclusive_Z_sumofweights);
110
111 scale(_h_dphi_jet_Z25_xs, crossSectionPerEvent());
112 scale(_h_dphi_jet_Z45_xs, crossSectionPerEvent());
113 scale(_h_dy_jet_Z25_xs, crossSectionPerEvent());
114 scale(_h_dy_jet_Z45_xs, crossSectionPerEvent());
115 scale(_h_yboost_jet_Z25_xs, crossSectionPerEvent());
116 scale(_h_yboost_jet_Z45_xs, crossSectionPerEvent());
117 }
118
119 /// @}
120
121
122 private:
123
124 /// @name Histograms (normalised)
125 /// @{
126 Histo1DPtr _h_dphi_jet_Z25;
127 Histo1DPtr _h_dphi_jet_Z45;
128
129 Histo1DPtr _h_dy_jet_Z25;
130 Histo1DPtr _h_dy_jet_Z45;
131
132 Histo1DPtr _h_yboost_jet_Z25;
133 Histo1DPtr _h_yboost_jet_Z45;
134 /// @}
135
136 /// @name Histograms (absolute cross sections)
137 /// @{
138 Histo1DPtr _h_dphi_jet_Z25_xs;
139 Histo1DPtr _h_dphi_jet_Z45_xs;
140
141 Histo1DPtr _h_dy_jet_Z25_xs;
142 Histo1DPtr _h_dy_jet_Z45_xs;
143
144 Histo1DPtr _h_yboost_jet_Z25_xs;
145 Histo1DPtr _h_yboost_jet_Z45_xs;
146 /// @}
147
148 CounterPtr _inclusive_Z_sumofweights;
149
150 };
151
152
153
154 RIVET_DECLARE_ALIASED_PLUGIN(D0_2009_S8349509, D0_2009_I826756);
155
156}
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