Rivet analyses referenceLHCB_2014_I1315113Relative production rates of $\chi_{b1}(1P)$ to $\chi_{b2}(1P)$ at 7 TeVExperiment: LHCB (LHC) Inspire ID: 1315113 Status: VALIDATED Authors:
Beam energies: (3500.0, 3500.0) GeV Run details:
Measurement of the relative rates of prompt $\chi_{b1}$ to $\chi_{b2}$ production at 7 TeV using the decay to $\Upsilon\gamma$ by the LHCb collaboration. Source code: LHCB_2014_I1315113.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4
5namespace Rivet {
6
7
8 /// @brief chi_b production at 7 TeV
9 class LHCB_2014_I1315113 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1315113);
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 ichi=0;ichi<2;++ichi) {
23 book(_h_chi[ichi],"TMP/h_CHI_"+toString(ichi),refData(1,1,1));
24 }
25 }
26
27
28 /// Perform the per-event analysis
29 void analyze(const Event& event) {
30 const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
31
32 for (const Particle& p : ufs.particles(Cuts::pid==20553 ||
33 Cuts::pid==555)) {
34 // Upsilon /gamma mode
35 if(p.children().size()!=2) continue;
36 Particle ups;
37 if(p.children()[0].pid()==22 && p.children()[1].pid()==553) {
38 ups = p.children()[1];
39 }
40 else if(p.children()[1].pid()==22 && p.children()[0].pid()==553) {
41 ups = p.children()[0];
42 }
43 else
44 continue;
45 double absrap=ups.absrap();
46 if(absrap<2. || absrap>4.5) continue;
47 unsigned int ichi = p.pid()==20553 ? 0 : 1;
48 _h_chi[ichi]->fill(ups.perp());
49 }
50 }
51
52
53 /// Normalise histograms etc., after the run
54 void finalize() {
55 vector<double> br = {.352,0.18};
56 for(unsigned int ix=0;ix<2;++ix)
57 scale(_h_chi[ix],1./br[ix]);
58 Estimate1DPtr tmp;
59 book(tmp,1,1,1);
60 divide(_h_chi[0],_h_chi[1],tmp);
61 tmp->scale(br[1]/br[0]);
62 }
63
64 /// @}
65
66
67 /// @name Histograms
68 /// @{
69 Histo1DPtr _h_chi[2];
70 /// @}
71
72
73 };
74
75
76 RIVET_DECLARE_PLUGIN(LHCB_2014_I1315113);
77
78}
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