Rivet analyses
Per-event yield of the highest transverse momentum charged particle and charged-particle jet
Experiment: CMS (LHC)
Inspire ID: 1380605
Status: VALIDATED
Authors: - Anastasia Grebenyuk - Hannes Jung
References: - arXiv: 1507.00233
Beams: p+ p+
Beam energies: (4000.0, 4000.0)GeV
Run details: - sqrts = 8 TeV, minbias events, no pT cut on partons
The per-event yield of the highest transverse momentum charged particle and charged-particle jet, integrated above a given pT min threshold starting at pT min = 0.8 and 1~GeV, respectively, is studied in pp collisions at $\sqrt{s} = 8$~. The particles and the jets are measured in the pseudorapidity ranges |η| < 2.4 and 1.9, respectively.
Source
code:CMS_2015_I1380605.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
namespace Rivet {
/// Per-event yield of the highest transverse momentum charged particle and charged-particle jet
class CMS_2015_I1380605 : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2015_I1380605);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
const ChargedFinalState cfs((Cuts::etaIn(-7., 7.)));
declare(cfs, "CFS");
declare(FastJets(cfs, JetAlg::ANTIKT, 0.5), "Jets");
book(_h_tracks, 1, 1, 1);
book(_h_jets , 2, 1, 1);
book(_ntracks, "ntracks");
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Veto events without forward activity on both sides
const ChargedFinalState& cfs = apply<ChargedFinalState>(event, "CFS");
const size_t count_plus = cfs.particles(Cuts::eta > 5.3 && Cuts::eta < 6.5).size();
const size_t count_minus = cfs.particles(Cuts::eta < -5.3 && Cuts::eta > -6.5).size();
if (!(count_plus > 0 || count_minus > 0)) vetoEvent; //< @todo Should this really also veto the jet analysis?
/// @warning Needs migration to an AO Counter
/// @note This isn't the number of tracks, it's the sum of event weights passing the veto
_ntracks->fill();
// Do track analysis here
// Find pttrackmax
double track_ptmax = 0;
for (const Particle& p : cfs.particles(Cuts::abseta < 2.4)) track_ptmax = max(track_ptmax, p.pT());
// Fill track analysis histograms
for (size_t i = 1; i <= _h_tracks->numBins(); ++i) {
const double binlimitlow_t = _h_tracks->bin(i).xMin();
const double weightbw_t = _h_tracks->bin(i).xWidth();
const double xbin_t = _h_tracks->bin(i).xMid();
if (track_ptmax > binlimitlow_t) _h_tracks -> fill(xbin_t, weightbw_t);
}
// Do jet analysis here
const Jets jetsdeta = apply<FastJets>(event,"Jets").jets(Cuts::pT > 1*GeV && Cuts::pT < 60*GeV && Cuts::abseta < 1.9);
// Find ptjetmax
double jet_ptmax = 0;
for (const Jet& j : jetsdeta) jet_ptmax = max(jet_ptmax, j.pT());
// Fill jet analysis histograms
for (size_t i = 1; i <= _h_jets->numBins(); ++i) {
const double binlimitlow_j = _h_jets->bin(i).xMin();
const double weightbw_j = _h_jets->bin(i).xWidth();
const double xbin_j = _h_jets->bin(i).xMid();
if (jet_ptmax > binlimitlow_j) _h_jets -> fill(xbin_j, weightbw_j);
}
}
/// Normalise histograms etc., after the run
void finalize() {
const double norm_t0 = _h_tracks->bin(8).sumW()/2.056170e-03/_h_tracks->bin(8).xWidth();
//const double norm_t1 = _h_tracks->bin(7).sumW()/2.056170e-03;
const double norm_j0 = _h_jets->bin(14).sumW()/3.575290e-03/_h_jets->bin(14).xWidth();
//const double norm_j1 = _h_jets->bin(13).sumW()/3.575290e-03;
if (norm_t0 > 0 ) scale(_h_tracks, 1./ norm_t0);
if (norm_j0 > 0 ) scale(_h_jets, 1./ norm_j0);
}
/// @}
private:
/// @name Histograms
/// @{
Histo1DPtr _h_tracks, _h_jets;
CounterPtr _ntracks;
/// @}
};
RIVET_DECLARE_PLUGIN(CMS_2015_I1380605);
}