Rivet analyses
Measurement of ATLAS track jet properties at 7 TeV
Experiment: ATLAS (LHC)
Inspire ID: 919017
Status: VALIDATED
Authors: - Seth Zenz - Andy Buckley
References: - Expt page: ATLAS-STDM-2010-14 - Phys.Rev.D 84 (2011) 054001 - DOI: 10.1103/PhysRevD.84.054001 - arXiv: 1107.3311 - Expt page: ATLAS-STDM-2010-14 - CERN-PH-EP-2011-110
Beams: p+ p+
Beam energies: (3500.0, 3500.0)GeV
Run details: - Min bias QCD at 7 TeV.
ATLAS measurement of track jet pT, multiplicity per jet, longitudinal fragmentation, transverse momentum, radius w.r.t jet axis distributions, with jets constructed from charged tracks with pT > 300 MeV, using the anti-kT jet algorithm with R = 0.4, 0.6.
Source
code:ATLAS_2011_I919017.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
namespace Rivet {
namespace {
inline double calcz(const Jet& j, const Particle& p) {
const double num = j.p3().dot(p.p3());
const double den = j.p3().mod2();
return min(num / den, 0.999999);
}
inline double calcptrel(const Jet& j, const Particle& p) {
const double num = j.p3().cross(p.p3()).mod();
const double den = j.p3().mod();
return num / den;
}
inline double calcr(const Jet& j, const Particle& p) {
return deltaR(j.rapidity(), j.phi(), p.rapidity(), p.phi());
}
// For annulus area kludge
/// @todo Improve somehow... need normalisation *without* bin width factors!
inline double calcrweight(const Jet& j, const Particle& p) {
size_t nBins_r = 26;
double bins_r[] = {0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.12, 0.14, 0.16,
0.18, 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60};
double r = calcr(j, p);
for (size_t bin = 0; bin < nBins_r; bin++) {
if (r < bins_r[bin + 1]) {
double up = bins_r[bin + 1];
double down = bins_r[bin];
return ((up - down) / (M_PI * (up * up - down * down)));
}
}
return 1.0;
}
}
class ATLAS_2011_I919017 : public Analysis {
public:
/// @name Constructors etc.
/// @{
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_I919017);
/// @}
public:
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
ChargedFinalState cfs((Cuts::etaIn(-2.5, 2.5) && Cuts::pT >= 0.3 * GeV));
FastJets trkjets04(cfs, JetAlg::ANTIKT, 0.4);
FastJets trkjets06(cfs, JetAlg::ANTIKT, 0.6);
declare(trkjets04, "Jets04");
declare(trkjets06, "Jets06");
// Book histograms
const vector<string> rapbins{"00_05_", "05_10_", "10_15_", "15_19_"};
const vector<string> ptbins{"04_06", "06_10", "10_15", "15_24", "24_40"};
for (const string R : {"04_", "06_"}) {
size_t iy = (R == "04_") ? 1 : 2;
book(_c[R + "sumw"], "/TMP/" + R + "sumw");
size_t irap = 0;
for (const string& rapbin : rapbins) {
++irap;
book(_hinc[R + rapbin], irap, 1, iy);
size_t ipt = 0;
for (const string& ptbin : ptbins) {
++ipt;
const string suff = R + rapbin + ptbin;
if (irap == 1) {
size_t offset = rapbins.size();
book(_h["N" + R + "00_19_" + ptbin], offset + ipt, 1, iy);
offset += ptbins.size() * ptbins.size();
book(_h["z" + R + "00_19_" + ptbin], offset + ipt, 1, iy);
offset += ptbins.size() * ptbins.size();
book(_h["ptrel" + R + "00_19_" + ptbin], offset + ipt, 1, iy);
offset += ptbins.size() * ptbins.size();
book(_h["rdA" + R + "00_19_" + ptbin], offset + ipt, 1, iy);
book(_c["numjets" + R + "00_19_" + ptbin], "/TMP/numjets" + R + "00_19_" + ptbin);
}
size_t offset = rapbins.size() + irap * ptbins.size();
book(_h["N" + suff], offset + ipt, 1, iy);
offset = rapbins.size() + (irap + ptbins.size()) * ptbins.size();
book(_h["z" + suff], offset + ipt, 1, iy);
offset = rapbins.size() + (irap + 2 * ptbins.size()) * ptbins.size();
book(_h["ptrel" + suff], offset + ipt, 1, iy);
offset = rapbins.size() + (irap + 3 * ptbins.size()) * ptbins.size();
book(_h["rdA" + suff], offset + ipt, 1, iy);
book(_c["numjets" + suff], "/TMP/numjets" + suff);
}
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
doCollection("04", event);
doCollection("06", event);
}
void doCollection(const string& Rval, const Event& event) {
const Jets& jets = apply<JetFinder>(event, "Jets" + Rval).jets();
if (jets.empty()) return;
const string R = Rval + "_";
_c[R + "sumw"]->fill();
for (const Jet& j : jets) {
const double jetpt = j.pT() / GeV;
const double jetrap = j.absrap();
string rapbin, ptbin;
if (jetrap >= 1.9) continue;
if (jetrap < 0.5)
rapbin = "00_05_";
else if (jetrap < 1.0)
rapbin = "05_10_";
else if (jetrap < 1.5)
rapbin = "10_15_";
else
rapbin = "15_19_";
_hinc[R + rapbin]->fill(jetpt);
if (inRange(jetpt, 4., 6.))
ptbin = "04_06";
else if (inRange(jetpt, 6., 10.))
ptbin = "06_10";
else if (inRange(jetpt, 10., 15.))
ptbin = "10_15";
else if (inRange(jetpt, 15., 24.))
ptbin = "15_24";
else if (inRange(jetpt, 24., 40.))
ptbin = "24_40";
else
continue;
fillgroup(j, R + "00_19_" + ptbin);
fillgroup(j, R + rapbin + ptbin);
} // each jet
}
void fillgroup(const Jet& j, const string& suff) {
_c["numjets" + suff]->fill();
_h["N" + suff]->fill(j.particles().size());
for (const Particle& p : j.particles()) {
_h["z" + suff]->fill(calcz(j, p));
_h["ptrel" + suff]->fill(calcptrel(j, p));
_h["rdA" + suff]->fill(calcr(j, p), calcrweight(j, p));
}
}
/// Normalise histograms etc., after the run
void finalize() {
const double xsec = crossSection() / microbarn;
for (auto& item : _hinc) {
if (item.first.substr(0, 2) == "04") {
double sf = _c["04_sumw"]->val();
if (item.first.substr(3, 2) == "15") sf *= 0.8;
if (sf)
scale(item.second, xsec / sf);
else
normalize(item.second, 0.0);
}
else {
double sf = _c["06_sumw"]->val();
if (item.first.substr(3, 2) == "15") sf *= 0.8;
if (sf)
scale(item.second, xsec / sf);
else
normalize(item.second, 0.0);
}
}
for (auto& item : _h) {
const string suff = item.first.substr(item.first.size() - 14);
const double sf = _c["numjets" + suff]->val();
if (sf)
scale(item.second, 1.0 / sf);
else
normalize(item.second, 0.0);
}
}
/// @}
private:
/// @name Histograms
/// @{
map<string, CounterPtr> _c;
map<string, Histo1DPtr> _h, _hinc;
/// @}
};
RIVET_DECLARE_PLUGIN(ATLAS_2011_I919017);
}