Rivet analyses referenceCMS_2011_I912560Measurement of ratio of the 3-jet over 2-jet cross section in $pp$ collisions at $\sqrt{s} = 7$ TeVExperiment: CMS (LHC) Inspire ID: 912560 Status: VALIDATED Authors:
Beam energies: (3500.0, 3500.0) GeV Run details:
A measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum, $H_T$, in the range $0.2 < H_T < 2.5$ TeV is presented. The data have been collected at a proton--proton centre-of-mass energy of 7 TeV with the CMS detector at the LHC, and correspond to an integrated luminosity of 36/pb. Jets are anti-$k_t$ with $R = 0.5$, $p_\perp > 50 \text{GeV}$ and $|\eta| < 2.5$. Source code: CMS_2011_I912560.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 ratio of 3-jet to 2-jet cross-sections
10 class CMS_2011_I912560 : public Analysis {
11 public:
12
13 RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2011_I912560);
14
15
16 void init() {
17 FinalState fs;
18 FastJets akt(fs, JetAlg::ANTIKT, 0.5);
19 declare(akt, "antikT");
20
21 book(_h_tmp_dijet , "TMP/dijet", refData(1, 1, 1));
22 book(_h_tmp_trijet, "TMP/trijet", refData(1, 1, 1));
23 book(_h_r32, 1, 1, 1);
24 }
25
26
27 void analyze(const Event & event) {
28
29 Jets highpT_jets;
30 double HT = 0;
31 for(const Jet & jet : apply<JetFinder>(event, "antikT").jetsByPt(Cuts::pT > 50.0*GeV)) {
32 if (jet.abseta() < 2.5) {
33 highpT_jets.push_back(jet);
34 HT += jet.pT();
35 }
36 }
37 if (highpT_jets.size() < 2) vetoEvent;
38 if (highpT_jets.size() >= 2) _h_tmp_dijet->fill(HT/TeV);
39 if (highpT_jets.size() >= 3) _h_tmp_trijet->fill(HT/TeV);
40 }
41
42
43 void finalize() {
44 divide(_h_tmp_trijet, _h_tmp_dijet, _h_r32);
45 }
46
47
48 private:
49
50 /// @{
51 Histo1DPtr _h_tmp_dijet, _h_tmp_trijet;
52 Estimate1DPtr _h_r32;
53 /// @}
54
55 };
56
57
58
59 RIVET_DECLARE_ALIASED_PLUGIN(CMS_2011_I912560, CMS_2011_S9088458);
60
61}
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