Rivet analyses
Differential cross sections for J/ψ and Υ(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⟂ and y) cross section for J/ψ and Υ(1, 2, 3S) production at 8 TeV by the LHCB collaboration.
Source
code:LHCB_2013_I1230344.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief J/psi and Upslion production at 8 TeV
class LHCB_2013_I1230344 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2013_I1230344);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
declare(UnstableParticles(), "UFS");
for(unsigned iy=0;iy<2;++iy)
book(_h_Jpsi_y[iy],2,1,iy+1);
for(unsigned int iy=0;iy<3;++iy) {
book(_h_Jpsi[iy],{2.0,2.5,3.0,3.5,4.0,4.5});
for(unsigned int ix=0;ix<5;++ix) {
if(iy<2)
book(_h_Jpsi[iy]->bin(ix+1),3+ix,1,1+iy);
else
book(_h_Jpsi[iy]->bin(ix+1),"TMP/Jpsi_"+toString(ix),refData(3+ix,1,1));
}
}
for(unsigned int iy=0;iy<3;++iy) {
book(_h_Ups_pT [iy], 9,1,iy+1);
book(_h_Ups_y [iy],10,1,iy+1);
book(_h_Ups_pT_r[iy],"TMP/Ups_pT_"+toString(iy),refData(16,1,1));
book(_h_Ups_y_r [iy],"TMP/Ups_y_" +toString(iy),refData(17,1,1));
book(_h_Ups[iy],{2.0,2.5,3.0,3.5,4.0,4.5});
for(unsigned int ix=0;ix<5;++ix) {
book(_h_Ups[iy]->bin(ix+1),11+ix,1,1+iy);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Final state of unstable particles to get particle spectra
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
// J/psi
for (const Particle& p : ufs.particles(Cuts::pid==443)) {
// prompt/non-prompt
bool nonPrompt = p.fromBottom();
double absrap = p.absrap();
double xp = p.perp();
if(absrap<2. || absrap>4.5 || xp>14.) continue;
_h_Jpsi_y[nonPrompt]->fill(absrap);
_h_Jpsi[nonPrompt] ->fill(absrap,xp);
_h_Jpsi[2 ] ->fill(absrap,xp);
}
// upsilon
for (const Particle& p : ufs.particles(Cuts::pid==553 or Cuts::pid==100553 or Cuts::pid==200553)) {
double absrap = p.absrap();
double xp = p.perp();
if(absrap<2. || absrap>4.5 || xp>15.) continue;
unsigned int iups=p.pid()/100000;
_h_Ups_pT[iups] ->fill(xp);
_h_Ups_y[iups] ->fill(absrap);
_h_Ups_pT_r[iups]->fill(xp);
_h_Ups_y_r[iups] ->fill(absrap);
_h_Ups[iups] ->fill(absrap,xp);
}
}
/// Normalise histograms etc., after the run
void finalize() {
// 1/2 due rapidity folding +/-
double factor = 0.5*crossSection()/nanobarn/sumOfWeights();
// branching ratios for upsilon
vector<double> br = {0.0248,0.0193,0.0218};
for(unsigned int ix=0;ix<2;++ix) {
scale(_h_Jpsi_y[ix],factor);
}
for(unsigned int ix=0;ix<3;++ix) {
scale(_h_Ups_pT [ix],factor*br[ix]);
scale(_h_Ups_y [ix],factor*br[ix]);
scale(_h_Ups_pT_r[ix],factor*br[ix]);
scale(_h_Ups_y_r [ix],factor*br[ix]);
scale(_h_Ups[ix] ,factor*1000.*br[ix]);
divByGroupWidth(_h_Ups[ix]);
scale(_h_Jpsi[ix],factor);
divByGroupWidth(_h_Jpsi[ix]);
}
for(unsigned int ix=0;ix<_h_Jpsi[0]->numBins();++ix) {
Estimate1DPtr tmp;
book(tmp,3+ix,1,3);
divide(_h_Jpsi[1]->bin(ix+1),_h_Jpsi[2]->bin(ix+1),tmp);
tmp->scale(100.);
}
for(unsigned int ix=0;ix<2;++ix) {
Estimate1DPtr tmp;
book(tmp,16,1,1+ix);
divide(_h_Ups_pT_r[ix+1],_h_Ups_pT_r[0],tmp);
book(tmp,17,1,1+ix);
divide(_h_Ups_y_r[ix+1],_h_Ups_y_r[0],tmp);
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_Jpsi_y[2],_h_Ups_pT[3],_h_Ups_y[3],_h_Ups_pT_r[3],_h_Ups_y_r[3];
Histo1DGroupPtr _h_Jpsi[3],_h_Ups[3];
/// @}
};
RIVET_DECLARE_PLUGIN(LHCB_2013_I1230344);
}