Rivet analyses referenceLHCB_2011_I891233Differential cross sections for J/ψ production at 7 TeVExperiment: LHCB (LHC) Inspire ID: 891233 Status: VALIDATED Authors:
Beam energies: (3500.0, 3500.0) GeV Run details:
Measurement of the double differential (in p⊥ and y) cross section for J/ψ production at 7 TeV by the LHCB collaboration. Source code: LHCB_2011_I891233.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4
5namespace Rivet {
6
7
8 /// @brief J/psi production at 7 TeV
9 class LHCB_2011_I891233 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2011_I891233);
14
15
16 /// @name Analysis methods
17 /// @{
18
19 /// Book histograms and initialise projections before the run
20 void init() {
21 declare(UnstableParticles(), "UFS");
22 for(unsigned int ix=0;ix<5;++ix) {
23 book(_h_Jpsi[ix],{2.0,2.5,3.0,3.5,4.0,4.5});
24 for(unsigned int iy=0;iy<5;++iy) {
25 if(ix<4)
26 book(_h_Jpsi[ix]->bin(iy+1),6+ix,1,iy+1);
27 else
28 book(_h_Jpsi[ix]->bin(iy+1),"TMP/JPsi_"+toString(iy),refData(6,1,iy+1));
29 }
30 }
31 }
32
33
34 /// Perform the per-event analysis
35 void analyze(const Event& event) {
36 // Final state of unstable particles to get particle spectra
37 const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
38 // J/psi
39 for (const Particle& p : ufs.particles(Cuts::pid==443)) {
40 // prompt/non-prompt
41 bool nonPrompt = p.fromBottom();
42 double absrap = p.absrap();
43 double xp = p.perp();
44 if(absrap<2. || absrap>4.5 || xp>14.) continue;
45 _h_Jpsi[4]->fill(absrap,xp);
46 if(nonPrompt) {
47 _h_Jpsi[1]->fill(absrap,xp);
48 }
49 else {
50 _h_Jpsi[0]->fill(absrap,xp);
51 _h_Jpsi[2]->fill(absrap,xp);
52 _h_Jpsi[3]->fill(absrap,xp);
53 }
54 }
55 }
56
57
58 /// Normalise histograms etc., after the run
59 void finalize() {
60 // 1/2 due rapidity folding +/-
61 double factor = 0.5*crossSection()/nanobarn/sumOfWeights();
62 for(unsigned int ix=0;ix<5;++ix) {
63 scale(_h_Jpsi[ix],factor);
64 divByGroupWidth(_h_Jpsi[ix]);
65 }
66 for(unsigned int ix=0;ix<_h_Jpsi[4]->numBins();++ix) {
67 Estimate1DPtr tmp;
68 book(tmp,10,1,ix+1);
69 divide(_h_Jpsi[1]->bin(ix+1),_h_Jpsi[4]->bin(ix+1),tmp);
70 tmp->scale(100.);
71 }
72 }
73
74 /// @}
75
76
77 /// @name Histograms
78 /// @{
79 Histo1DGroupPtr _h_Jpsi[5];
80 /// @}
81
82
83 };
84
85
86 RIVET_DECLARE_PLUGIN(LHCB_2011_I891233);
87
88}
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