Rivet analyses referenceATLAS_2016_CONF_2016_037Search for SUSY in 13 \text{TeV} events with 2 or 3 leptons and multiple jetsExperiment: ATLAS (LHC) Status: UNVALIDATED Authors:
Beams: p+ p+ Beam energies: (6500.0, 6500.0) GeV Run details:
A search for strongly produced supersymmetric particles using signatures involving multiple energetic jets and either two isolated same-sign leptons ($e$ or $\mu$) or at least three isolated leptons. The analysis also utilises other observables, such as $b$-tagged jets or missing transverse momentum, to extend its sensitivity. A data sample of proton--proton collisions at $\sqrt{s} = 13 \text{TeV}$ recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to a total integrated luminosity of 13.2/fb, is used for the search. No significant excess over the Standard Model expectation is observed. Source code: ATLAS_2016_CONF_2016_037.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/PromptFinalState.hh"
5#include "Rivet/Projections/FastJets.hh"
6#include "Rivet/Projections/Sphericity.hh"
7#include "Rivet/Projections/SmearedParticles.hh"
8#include "Rivet/Projections/SmearedJets.hh"
9#include "Rivet/Projections/SmearedMET.hh"
10namespace Rivet {
11
12
13 /// @brief ATLAS 2016 2 -SS-lepton / 3-lepton SUSY search, from 13.2/fb CONF note
14 class ATLAS_2016_CONF_2016_037 : public Analysis {
15 public:
16
17 /// Constructor
18 RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2016_CONF_2016_037);
19
20
21 /// @name Analysis methods
22 /// @{
23
24 /// Book histograms and initialise projections before the run
25 void init() {
26
27 // Initialise and register projections
28 FinalState calofs(Cuts::abseta < 4.9);
29 declare(calofs, "Clusters");
30 FastJets fj(calofs, JetAlg::ANTIKT, 0.4);
31 declare(fj, "TruthJets");
32 declare(SmearedJets(fj, JET_SMEAR_ATLAS_RUN2, [](const Jet& j) {
33 if (j.abseta() > 2.5) return 0.;
34 return j.bTagged(Cuts::pT > 5*GeV) ? 0.70 :
35 j.cTagged(Cuts::pT > 5*GeV) ? 1/12. :
36 j.tauTagged(Cuts::pT > 5*GeV) ? 1/54. : 1/380.; }), "Jets");
37
38 MissingMomentum mm(calofs);
39 declare(mm, "TruthMET");
40 declare(SmearedMET(mm, MET_SMEAR_ATLAS_RUN2), "MET");
41
42 FinalState es(Cuts::abspid == PID::ELECTRON && Cuts::abseta < 2.47 && !Cuts::absetaIn(1.37, 1.52) && Cuts::pT > 10*GeV);
43 declare(es, "TruthElectrons");
44 declare(SmearedParticles(es, ELECTRON_RECOEFF_ATLAS_RUN2, ELECTRON_SMEAR_ATLAS_RUN2), "Electrons");
45
46 FinalState mus(Cuts::abspid == PID::MUON && Cuts::abseta < 2.5 && Cuts::pT > 10*GeV);
47 declare(mus, "TruthMuons");
48 declare(SmearedParticles(mus, MUON_EFF_ATLAS_RUN2, MUON_SMEAR_ATLAS_RUN2), "Muons");
49
50 FinalState cfs(Cuts::abseta < 2.5 && Cuts::abscharge > 0);
51 declare(cfs, "TruthTracks");
52 declare(SmearedParticles(cfs, TRK_EFF_ATLAS_RUN2), "Tracks");
53
54
55 // Book histograms/counters
56 book(_h_3l1,"SR3l1");
57 book(_h_3l2,"SR3l2");
58 book(_h_0b1,"SR0b1");
59 book(_h_0b2,"SR0b2");
60 book(_h_1b,"SR1b");
61 book(_h_3b,"SR3b");
62 book(_h_1bDD,"SR1bDD");
63 book(_h_3bDD,"SR3bDD");
64 book(_h_1bGG,"SR1bGG");
65
66 }
67
68
69 /// Perform the per-event analysis
70 void analyze(const Event& event) {
71
72 // Get baseline electrons, muons, and jets
73 Particles elecs = apply<ParticleFinder>(event, "Electrons").particlesByPt();
74 Particles muons = apply<ParticleFinder>(event, "Muons").particlesByPt();
75 Jets jets = apply<JetFinder>(event, "Jets").jetsByPt(Cuts::pT > 20*GeV && Cuts::abseta < 2.8);
76 const Jets bjets = select(jets, [&](const Jet& j) { return j.bTagged(Cuts::pT > 5*GeV); });
77
78
79 // Jet/electron/muon overlap removal and selection
80 // Remove any electron or muon within dR = 0.2 of a b-tagged jet
81 for (const Jet& bj : bjets) {
82 idiscard(elecs, deltaRLess(bj, 0.2, RAPIDITY));
83 idiscard(muons, deltaRLess(bj, 0.2, RAPIDITY));
84 }
85 // Remove any untagged jet within dR = 0.2 of an electron or muon
86 for (const Particle& e : elecs)
87 idiscard(jets, deltaRLess(e, 0.2, RAPIDITY));
88 for (const Particle& m : muons)
89 idiscard(jets, deltaRLess(m, 0.2, RAPIDITY));
90 // Remove any untagged low-multiplicity/muon-dominated jet within dR = 0.4 of a muon
91 for (const Particle& m : muons)
92 idiscard(jets, [&](const Jet& j) {
93 if (deltaR(m, j, RAPIDITY) > 0.4) return false;
94 const Particles trks = j.particles(Cuts::abscharge != 0);
95 if (trks.size() < 3) return true;
96 return m.pT()/j.pT() > 0.5 && m.pT()/sum(trks, pT, 0.0) > 0.7;
97 });
98 // Remove any electron or muon near a remaining jet, with a shrinking cone
99 const auto lcone_iso_fn = [&](const Particle& l) {
100 const double dr = min(0.4, 0.04 + 10*GeV/l.pT());
101 return any(jets, deltaRLess(l, dr, RAPIDITY));
102 };
103 idiscard(elecs, lcone_iso_fn);
104 idiscard(muons, lcone_iso_fn);
105 // Track-sharing e,mu also filtered, but that decision can't be made here
106 const Jets& sigjets = jets;
107 const Jets& sigbjets = bjets;
108
109
110 // Lepton isolation
111 Particles sigelecs = select(elecs, Cuts::abseta < 2);
112 Particles sigmuons = muons;
113 iselect(sigelecs, ParticleEffFilter(ELECTRON_EFF_ATLAS_RUN2_MEDIUM));
114 const Particles trks = apply<ParticleFinder>(event, "Tracks").particles();
115 const Particles clus = apply<ParticleFinder>(event, "Clusters").particles();
116 idiscard(sigelecs, [&](const Particle& e) {
117 const double R = min(0.2, 10*GeV/e.pT());
118 double ptsum = -e.pT(), etsum = -e.Et();
119 for (const Particle& t : trks)
120 if (deltaR(t,e) < R) ptsum += t.pT();
121 for (const Particle& c : clus)
122 if (deltaR(c,e) < 0.2) etsum += c.pT(); ///< @todo Bit vague about "energy"
123 return ptsum / e.pT() > 0.06 || etsum / e.pT() > 0.06;
124 });
125 idiscard(sigmuons, [&](const Particle& m) {
126 const double R = min(0.3, 10*GeV/m.pT());
127 double ptsum = -m.pT();
128 for (const Particle& t : trks)
129 if (deltaR(t,m) < R) ptsum += t.pT();
130 return ptsum / m.pT() > 0.06;
131 });
132 /// @todo Note is vague about whether "signal lepton" defn includes pT > 20?
133 idiscard(sigelecs, Cuts::pT > 20*GeV);
134 idiscard(sigmuons, Cuts::pT > 20*GeV);
135
136
137 // MET calculation (NB. done generically, with smearing, rather than via explicit physics objects)
138 const Vector3 vmet = -apply<SmearedMET>(event, "MET").vectorEt();
139 const double etmiss = vmet.mod();
140
141
142 //////////////////
143
144
145 // Event selection cuts
146 const Particles sigleptons = sigelecs + sigmuons;
147 if (sigleptons.size() < 2) vetoEvent;
148 if (sigleptons.size() == 2 && sigleptons[0].charge() != sigleptons[1].charge()) vetoEvent;
149
150 // Jet sub-selections and meff calculation
151 const Jets sigjets25 = select(sigjets, Cuts::pT > 25*GeV);
152 const Jets sigjets40 = select(sigjets25, Cuts::pT > 40*GeV);
153 const Jets sigjets50 = select(sigjets40, Cuts::pT > 50*GeV);
154 /// @todo Is meff specific to the jet pT cut?
155 const double meff = sum(sigjets, pT, 0.0) + sum(sigleptons, pT, 0.0);
156
157 // Fill counters
158 if (sigleptons.size() >= 3 && sigbjets.empty() && sigjets40.size() >= 4 && etmiss > 150*GeV) _h_3l1->fill();
159 if (sigleptons.size() >= 3 && sigbjets.empty() && sigjets40.size() >= 4 && etmiss > 200*GeV && meff > 1500*GeV) _h_3l2->fill();
160 if (sigleptons.size() >= 2 && sigbjets.empty() && sigjets25.size() >= 6 && etmiss > 150*GeV && meff > 500*GeV) _h_0b1->fill();
161 if (sigleptons.size() >= 2 && sigbjets.empty() && sigjets40.size() >= 6 && etmiss > 150*GeV && meff > 900*GeV) _h_0b2->fill();
162 if (sigleptons.size() >= 2 && sigbjets.size() >= 1 && sigjets25.size() >= 6 && etmiss > 200*GeV && meff > 650*GeV) _h_1b->fill();
163 if (sigleptons.size() >= 2 && sigbjets.size() >= 3 && sigjets25.size() >= 6 && etmiss > 150*GeV && meff > 600*GeV) _h_3b->fill();
164 if (select(sigleptons, Cuts::charge < 0).size() >= 2) {
165 if (sigleptons.size() >= 2 && sigbjets.size() >= 1 && sigjets50.size() >= 6 && meff > 1200*GeV) _h_1bDD->fill();
166 if (sigleptons.size() >= 2 && sigbjets.size() >= 3 && sigjets50.size() >= 6 && meff > 1000*GeV) _h_3bDD->fill();
167 if (sigleptons.size() >= 2 && sigbjets.size() >= 1 && sigjets50.size() >= 6 && meff > 1800*GeV) _h_1bGG->fill();
168 }
169
170 }
171
172
173 /// Normalise counters after the run
174 void finalize() {
175
176 const double sf = 13.2*crossSection()/femtobarn/sumOfWeights();
177 scale(_h_3l1, sf); scale(_h_3l2, sf); scale(_h_0b1, sf);
178 scale(_h_0b2, sf); scale(_h_1b, sf); scale(_h_3b, sf);
179 scale(_h_1bDD, sf); scale(_h_3bDD, sf); scale(_h_1bGG, sf);
180
181 }
182
183 /// @}
184
185
186 private:
187
188 /// @name Histograms
189 /// @{
190 CounterPtr _h_3l1, _h_3l2, _h_0b1, _h_0b2, _h_1b, _h_3b, _h_1bDD, _h_3bDD, _h_1bGG;
191 /// @}
192
193
194 };
195
196
197
198 RIVET_DECLARE_PLUGIN(ATLAS_2016_CONF_2016_037);
199
200
201}
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