Rivet analyses referenceATLAS_2016_I1487726Collinear W emissions at 8 TeVExperiment: ATLAS (LHC) Inspire ID: 1487726 Status: VALIDATED Authors:
Beam energies: (4000.0, 4000.0) GeV Run details:
The $W$ boson angular distribution in events with high transverse momentum jets is measured using data collected by the ATLAS experiment from proton-proton collisions at a centre-of-mass energy $\sqrt{s}=8$ TeV at the Large Hadron Collider, corresponding to an integrated luminosity of 20.3 fb$^{-1}$. The focus is on the contributions to $W+$jets processes from real $W$ emission, which is achieved by studying events where a muon is observed close to a high transverse momentum jet. At small angular separations, these contributions are expected to be large. Various theoretical models of this process are compared to the data in terms of the absolute cross-section and the angular distributions of the muon from the leptonic $W$ decay. Source code: ATLAS_2016_I1487726.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/FinalState.hh"
4#include "Rivet/Projections/DressedLeptons.hh"
5#include "Rivet/Projections/FastJets.hh"
6
7namespace Rivet {
8
9
10class ATLAS_2016_I1487726 : public Analysis {
11
12 public:
13
14 /// Constructor
15 /// @brief Collinear W emissions at 8 TeV
16 RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2016_I1487726);
17
18 public:
19
20 /// @name Analysis methods
21 //@{
22
23 /// Book histograms and initialise projections before the run
24 void init() {
25
26 _mode = 0;
27 if ( getOption("LMODE") == "EL" ) _mode = 1;
28
29 // These really should include non-prompt leptons/photons
30 FinalState mufs(Cuts::abspid == PID::MUON);
31 FinalState elfs(Cuts::abspid == PID::ELECTRON);
32 FinalState phs(Cuts::abspid == PID::PHOTON);
33
34 Cut lep_fid = (Cuts::abseta < 2.4 && Cuts::pT >= 25*GeV);
35 DressedLeptons dlep(phs, _mode? elfs : mufs, 0.1, lep_fid, true);
36 declare(dlep, "DressedLeptons");
37
38 FastJets fj(FinalState(), FastJets::ANTIKT, 0.4, JetAlg::Muons::NONE, JetAlg::Invisibles::NONE);
39 declare(fj, "AntiKt4Jets");
40
41 book(h_mu_jet_dr, 2, 1, 1);
42 book(h_mu_jet_dr_pt500600, 4, 1, 1);
43 book(h_mu_jet_dr_pt650, 5, 1, 1);
44 }
45
46
47 /// Perform the per-event analysis
48 void analyze(const Event& event) {
49
50 const vector<DressedLepton> leptons = apply<DressedLeptons>(event, "DressedLeptons").dressedLeptons();
51 const Jets jets = apply<FastJets>(event, "AntiKt4Jets").jetsByPt(Cuts::pT >= 100*GeV && Cuts::abseta <= 2.1);
52
53 if (leptons.size() != 1) vetoEvent;
54 if (jets.size() < 1) vetoEvent;
55 if (jets[0].pt() < 500.0*GeV) vetoEvent;
56
57 // find closest jet to the lepton.
58 Jet jet;
59 double drmin = 999;
60 for (const Jet &j : jets) {
61 double dr = deltaR(leptons[0], j);
62 if (dr < drmin) {
63 drmin = dr;
64 jet = j;
65 }
66 }
67
68 h_mu_jet_dr->fill(drmin);
69 if (jets[0].pT() > 650*GeV) h_mu_jet_dr_pt650->fill(drmin);
70 else if (jets[0].pT() > 500*GeV && jets[0].pT() < 600*GeV) {
71 h_mu_jet_dr_pt500600->fill(drmin);
72 }
73 }
74
75 /// Normalise histograms etc., after the run
76 void finalize() {
77 const double sf = crossSection() / femtobarn / sumOfWeights();
78 scale(h_mu_jet_dr, sf);
79 scale(h_mu_jet_dr_pt500600, sf);
80 scale(h_mu_jet_dr_pt650, sf);
81 }
82
83 //@}
84
85 protected:
86
87 size_t _mode;
88
89 private:
90
91 /// @name Histograms
92 //@{
93 Histo1DPtr h_mu_jet_dr;
94 Histo1DPtr h_mu_jet_dr_pt500600;
95 Histo1DPtr h_mu_jet_dr_pt650;
96 //@}
97 };
98
99
100 // The hook for the plugin system
101 RIVET_DECLARE_PLUGIN(ATLAS_2016_I1487726);
102}
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