rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

LHCB_2013_I1230344

Differential cross sections for $J/\psi$ and $\Upsilon(1,2,3S)$ production at 8 TeV
Experiment: LHCB (LHC)
Inspire ID: 1230344
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • JHEP 06 (2013) 064, 2013
Beams: p+ p+
Beam energies: (4000.0, 4000.0) GeV
Run details:
  • hadronic events with Jpsi and Upsilon production

Measurement of the double differential (in $p_\perp$ and $y$) cross section for $J/\psi$ and $\Upsilon(1,2,3S)$ production at 8 TeV by the LHCB collaboration.

Source code: LHCB_2013_I1230344.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/UnstableParticles.hh"
  4
  5namespace Rivet {
  6
  7
  8  /// @brief J/psi and Upslion production at 8 TeV
  9  class LHCB_2013_I1230344 : public Analysis {
 10  public:
 11
 12    /// Constructor
 13    RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2013_I1230344);
 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 iy=0;iy<2;++iy) 
 23	book(_h_Jpsi_y[iy],2,1,iy+1);
 24      for(unsigned int iy=0;iy<3;++iy) {
 25        book(_h_Jpsi[iy],{2.0,2.5,3.0,3.5,4.0,4.5});
 26        for(unsigned int ix=0;ix<5;++ix) {
 27          if(iy<2)
 28            book(_h_Jpsi[iy]->bin(ix+1),3+ix,1,1+iy);
 29          else
 30            book(_h_Jpsi[iy]->bin(ix+1),"TMP/Jpsi_"+toString(ix),refData(3+ix,1,1));
 31        }
 32      }
 33      for(unsigned int iy=0;iy<3;++iy) {
 34	book(_h_Ups_pT  [iy], 9,1,iy+1);
 35	book(_h_Ups_y   [iy],10,1,iy+1);
 36	book(_h_Ups_pT_r[iy],"TMP/Ups_pT_"+toString(iy),refData(16,1,1));
 37	book(_h_Ups_y_r [iy],"TMP/Ups_y_" +toString(iy),refData(17,1,1));
 38        book(_h_Ups[iy],{2.0,2.5,3.0,3.5,4.0,4.5});
 39	for(unsigned int ix=0;ix<5;++ix) {
 40          book(_h_Ups[iy]->bin(ix+1),11+ix,1,1+iy);
 41	}
 42      }
 43    }
 44
 45
 46    /// Perform the per-event analysis
 47    void analyze(const Event& event) {
 48
 49      // Final state of unstable particles to get particle spectra
 50      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
 51      // J/psi
 52      for (const Particle& p : ufs.particles(Cuts::pid==443)) {
 53	// prompt/non-prompt
 54	bool nonPrompt = p.fromBottom();
 55        double absrap = p.absrap();
 56        double xp = p.perp();
 57	if(absrap<2. || absrap>4.5 ||  xp>14.) continue;
 58	_h_Jpsi_y[nonPrompt]->fill(absrap);
 59	_h_Jpsi[nonPrompt]  ->fill(absrap,xp);
 60	_h_Jpsi[2        ]  ->fill(absrap,xp);
 61      }
 62      // upsilon
 63      for (const Particle& p : ufs.particles(Cuts::pid==553 or Cuts::pid==100553 or Cuts::pid==200553)) {
 64        double absrap = p.absrap();
 65        double xp = p.perp();
 66	if(absrap<2. || absrap>4.5 ||  xp>15.) continue;
 67	unsigned int iups=p.pid()/100000;
 68	_h_Ups_pT[iups]  ->fill(xp);
 69	_h_Ups_y[iups]   ->fill(absrap);
 70	_h_Ups_pT_r[iups]->fill(xp);
 71	_h_Ups_y_r[iups] ->fill(absrap);
 72	_h_Ups[iups]     ->fill(absrap,xp);	
 73      }
 74      
 75    }
 76
 77
 78    /// Normalise histograms etc., after the run
 79    void finalize() {
 80      // 1/2 due rapidity folding +/-
 81      double factor = 0.5*crossSection()/nanobarn/sumOfWeights();
 82      // branching ratios for upsilon
 83      vector<double> br = {0.0248,0.0193,0.0218};
 84      for(unsigned int ix=0;ix<2;++ix) {
 85	scale(_h_Jpsi_y[ix],factor);
 86      }
 87      for(unsigned int ix=0;ix<3;++ix) {
 88	scale(_h_Ups_pT  [ix],factor*br[ix]);
 89	scale(_h_Ups_y   [ix],factor*br[ix]);
 90	scale(_h_Ups_pT_r[ix],factor*br[ix]);
 91	scale(_h_Ups_y_r [ix],factor*br[ix]);
 92	scale(_h_Ups[ix] ,factor*1000.*br[ix]);
 93        divByGroupWidth(_h_Ups[ix]);
 94	scale(_h_Jpsi[ix],factor);
 95        divByGroupWidth(_h_Jpsi[ix]);
 96      }
 97      for(unsigned int ix=0;ix<_h_Jpsi[0]->numBins();++ix) {
 98	Estimate1DPtr tmp;
 99	book(tmp,3+ix,1,3);
100	divide(_h_Jpsi[1]->bin(ix+1),_h_Jpsi[2]->bin(ix+1),tmp);
101	tmp->scale(100.);
102      }
103      for(unsigned int ix=0;ix<2;++ix) {
104	Estimate1DPtr tmp;
105	book(tmp,16,1,1+ix);
106	divide(_h_Ups_pT_r[ix+1],_h_Ups_pT_r[0],tmp);
107	book(tmp,17,1,1+ix);
108	divide(_h_Ups_y_r[ix+1],_h_Ups_y_r[0],tmp);
109      }
110    }
111
112    /// @}
113
114
115    /// @name Histograms
116    /// @{
117    Histo1DPtr _h_Jpsi_y[2],_h_Ups_pT[3],_h_Ups_y[3],_h_Ups_pT_r[3],_h_Ups_y_r[3];
118    Histo1DGroupPtr _h_Jpsi[3],_h_Ups[3];
119    /// @}
120
121
122  };
123
124
125  RIVET_DECLARE_PLUGIN(LHCB_2013_I1230344);
126
127}