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LHCB_2014_I1280929

$\Upsilon(1,2,3S)$ production at 2.76 TeV
Experiment: LHCB (LHC)
Inspire ID: 1280929
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Eur.Phys.J.C 74 (2014) 4, 2835
Beams: p+ p+
Beam energies: (1380.0, 1380.0) GeV
Run details:
  • hadronic events with Upsilon production

Measurement of the differential (in $p_\perp$ and $y$) cross section for $\Upsilon(1,2,3S)$ production at 2.76 TeV by the LHCB collaboration.

Source code: LHCB_2014_I1280929.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/UnstableParticles.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Upsilon production at 2.76 TeV
 9  class LHCB_2014_I1280929 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1280929);
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 iups=0;iups<3;++iups) {
23	book(_h_Ups_pT [iups],3+iups,1,1);
24	book(_h_Ups_y  [iups],6+iups,1,1);
25	book(_h_Ups_y_r[iups],"TMP/UPS_y_"+toString(iups),refData(10,1,1));
26
27      }
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      // Final state of unstable particles to get particle spectra
34      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
35      // upsilon
36      for (const Particle& p : ufs.particles(Cuts::pid==553 or Cuts::pid==100553 or Cuts::pid==200553)) {
37        double absrap = p.absrap();
38        double xp = p.perp();
39	if(absrap<2. || absrap>4.5 ||  xp>15.) continue;
40	unsigned int iups=p.pid()/100000;
41	_h_Ups_pT[iups]  ->fill(xp);
42	_h_Ups_y[iups]   ->fill(absrap);
43	_h_Ups_y_r[iups] ->fill(absrap);
44      }
45    }
46
47
48    /// Normalise histograms etc., after the run
49    void finalize() {
50      // 1/2 due rapidity folding +/-
51      double factor = 0.5*crossSection()/nanobarn/sumOfWeights();
52      // branching ratios for upsilon
53      vector<double> br = {0.0248,0.0193,0.0218};
54      for(unsigned int ix=0;ix<3;++ix) {
55	scale(_h_Ups_pT  [ix],factor*br[ix]);
56	scale(_h_Ups_y   [ix],factor*br[ix]); 
57	scale(_h_Ups_y_r [ix],factor*br[ix]);
58      }
59      for(unsigned int ix=0;ix<2;++ix) {
60	Estimate1DPtr tmp;
61	book(tmp,9,1,1+ix);
62	divide(_h_Ups_pT[ix+1],_h_Ups_pT[0],tmp);
63	book(tmp,10,1,1+ix);
64	divide(_h_Ups_y_r[ix+1],_h_Ups_y_r[0],tmp);
65      }
66    }
67
68    /// @}
69
70
71    /// @name Histograms
72    /// @{
73    Histo1DPtr _h_Ups_pT[3],_h_Ups_y[3],_h_Ups_y_r[3];
74    /// @}
75
76
77  };
78
79
80  RIVET_DECLARE_PLUGIN(LHCB_2014_I1280929);
81
82}