Rivet analyses referenceCMS_2012_I1089835Inclusive b-jet production in pp collisions at 7 TeVExperiment: CMS (LHC) Inspire ID: 1089835 Status: VALIDATED Authors:
Beam energies: (3500.0, 3500.0) GeV Run details:
The inclusive b-jet production cross section in pp collisions at a center-of-mass energy of 7 TeV is measured using data collected by the CMS experiment at the LHC. The cross section is presented as a function of the jet transverse momentum in the range 18 $<$ pT $<$ 200 GeV for several rapidity intervals. The results are also given as the ratio of the b-jet production cross section to the inclusive jet production cross section. The measurement is performed with two different analyses, which differ in their trigger selection and b-jet identification: a jet analysis that selects events with a b jet using a sample corresponding to an integrated luminosity of 34 inverse picobarns, and a muon analysis requiring a b jet with a muon based on an integrated luminosity of 3 inverse picobarns. In both approaches the b jets are identified by requiring a secondary vertex. The results from the two methods are in agreement with each other and with next-to-leading order calculations, as well as with predictions based on the PYTHIA event generator. Source code: CMS_2012_I1089835.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Tools/Logging.hh"
4#include "Rivet/Projections/FinalState.hh"
5#include "Rivet/Projections/FastJets.hh"
6
7namespace Rivet {
8
9
10 /// @brief Inclusive b-jet production in pp collisions at 7 TeV
11 class CMS_2012_I1089835 : public Analysis {
12 public:
13
14 /// Constructor
15 RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2012_I1089835);
16
17
18 /// @name Analysis methods
19 /// @{
20
21 /// Book histograms and initialise projections before the run
22 void init() {
23
24 const FinalState cnfs;
25 declare(cnfs, "FS");
26 declare(FastJets(cnfs, JetAlg::ANTIKT, 0.5), "Jets");
27
28 book(_h_dsigdpty05, 4, 1, 1);
29 book(_h_dsigdpty10, 5, 1, 1);
30 book(_h_dsigdpty15, 6, 1, 1);
31 book(_h_dsigdpty20, 7, 1, 1);
32 book(_h_dsigdpty22, 8, 1, 1);
33
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39
40 const FastJets& fastjets = apply<FastJets>(event, "Jets");
41 const Jets jets = fastjets.jetsByPt(Cuts::pT > 10*GeV);
42
43 for (const Jet& j : jets) {
44
45 const double ptB= j.pT();
46 const double yB= j.rapidity();
47
48 if (j.bTagged()) {
49
50 if( fabs(yB) < 0.5) { _h_dsigdpty05->fill( ptB, 1.0 );}
51 else if( fabs(yB) >= 0.5 && fabs(yB) < 1.0) { _h_dsigdpty10->fill( ptB, 1.0 );}
52 else if( fabs(yB) >= 1.0 && fabs(yB) < 1.5) { _h_dsigdpty15->fill( ptB, 1.0 );}
53 else if( fabs(yB) >= 1.5 && fabs(yB) < 2.0) { _h_dsigdpty20->fill( ptB, 1.0 );}
54 else if( fabs(yB) >= 2.0 && fabs(yB) < 2.2) { _h_dsigdpty22->fill( ptB, 1.0 );}
55 }
56 }
57 }
58
59 /// Normalise histograms etc., after the run
60 void finalize() {
61
62 double invlumi = crossSection()/picobarn/sumOfWeights();
63
64 scale(_h_dsigdpty05, invlumi);
65 scale(_h_dsigdpty10, invlumi);
66 scale(_h_dsigdpty15, invlumi);
67 scale(_h_dsigdpty20, invlumi);
68 scale(_h_dsigdpty22, invlumi/0.4);
69
70 }
71
72 /// @}
73
74
75 private:
76
77 /// @name Histograms
78 /// @{
79 Histo1DPtr _h_dsigdpty05;
80 Histo1DPtr _h_dsigdpty10;
81 Histo1DPtr _h_dsigdpty15;
82 Histo1DPtr _h_dsigdpty20;
83 Histo1DPtr _h_dsigdpty22;
84 /// @}
85
86 };
87
88
89 RIVET_DECLARE_PLUGIN(CMS_2012_I1089835);
90
91}
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