Rivet analyses

title: CDF_2001_I538041

Two jet triply-differential cross-section

Experiment: CDF (Tevatron Run 1)

Inspire ID: 538041

Status: VALIDATED

Authors: - Frank Siegert

References: - Phys.Rev.D64:012001,2001 - DOI: 10.1103/PhysRevD.64.012001 - arXiv: hep-ex/0012013

Beams: p- p+

Beam energies: (900.0, 900.0)GeV

Run details: - Dijet events at Tevatron with $\sqrt{s}=1.8$ TeV

A measurement of the two-jet differential cross section, $\mathrm{d}^3\sigma/\mathrm{d}E_T \, \mathrm{d}\eta_1 \, \mathrm{d}\eta_2$, based on an integrated luminosity of $86 \mathrm{pb}^{-1}$. The differential cross section is measured as a function of the transverse energy, $E_\perp$, of a jet in the pseudorapidity region $0.1 < |\eta_1| < 0.7$ for four different pseudorapidity bins of a second jet restricted to $0.1 < |\eta_2| < 3.0$.

Source code:CDF_2001_I538041.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// @brief CDF two-jet triply-differential cross-section class CDF_2001_I538041 : public Analysis { public:

RIVET_DEFAULT_ANALYSIS_CTOR(CDF_2001_I538041);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {
  FinalState fs(Cuts::abseta < 4.2);
  declare(FastJets(fs, JetAlg::CDFJETCLU, 0.7), "Jets");

  book(_h_ET, {0.1, 0.7, 1.4, 2.1, 3.0}, {"d01-x01-y01", "d02-x01-y01", "d03-x01-y01", "d04-x01-y01"});
  _etaxes.resize(4);
  _etaxes[0] = YODA::Axis<double>{41.0,   47.0,  54.45, 67.2,   84.9,   100.45, 113.05, 126.0,
                                  141.65, 162.6, 191.9, 236.75, 291.15, 350.3,  414.5};
  _etaxes[1] = YODA::Axis<double>{39.9,  46.3,  54.0,   66.85, 84.6,  100.1, 112.65, 125.55,
                                  141.0, 161.6, 190.05, 233.7, 287.1, 343.8, 404.0};
  _etaxes[2] = YODA::Axis<double>{38.7,   45.5,  53.45, 66.15, 83.65,  98.95, 111.2,
                                  123.75, 138.7, 158.6, 185.3, 226.75, 278.65};
  _etaxes[3] = YODA::Axis<double>{37.6,  44.2,  51.85,  63.95, 81.05,  96.1,
                                  108.0, 120.1, 134.25, 153.1, 177.55, 205.25};
}


/// Perform the per-event analysis
void analyze(const Event& event) {

  if (_edges.empty()) {
    _edges.resize(_h_ET->numBins());
    for (const auto& b : _h_ET->bins()) {
      _edges[b.index() - 1] = b->xEdges();
    }
  }

  Jets jets = apply<FastJets>(event, "Jets").jets(Cuts::Et > 10 * GeV, cmpMomByEt);
  if (jets.size() < 2) vetoEvent;
  FourMomentum jet1 = jets[0].momentum();
  FourMomentum jet2 = jets[1].momentum();
  double eta1 = jet1.abseta();
  double eta2 = jet2.abseta();
  double ET1 = jet1.Et();
  double ET2 = jet2.Et();
  if (!inRange(eta1, 0.1, 0.7) || ET1 < 40.0 * GeV) vetoEvent;
  if (!inRange(eta2, 0.1, 3.0)) vetoEvent;
  discfill(eta2, ET1);
  if (eta2 < 0.7 && ET2 > 40.0 * GeV) discfill(eta1, ET2);
}


void discfill(const double eta, const double ET) {
  string edge = "OTHER";
  const size_t eta_idx = _h_ET->binAt(eta).index();
  if (eta_idx && eta_idx <= _h_ET->numBins()) {
    // eta bin is in visible range
    const size_t et_idx = _etaxes[eta_idx - 1].index(ET);
    if (et_idx && et_idx <= _edges[eta_idx - 1].size()) {
      // ET bin along this eta bin is also in visible range
      edge = _edges[eta_idx - 1][et_idx - 1];
    }
  }
  _h_ET->fill(eta, edge);
}

/// Normalise histograms etc., after the run
void finalize() {
  const double deta1 = 1.2;
  scale(_h_ET, crossSection() / nanobarn / sumOfWeights() / deta1 / 2.0);
  divByGroupWidth(_h_ET);
  for (auto& h : _h_ET->bins()) {
    for (auto& b : h->bins()) {
      b.scaleW(1.0 / _etaxes[h.index() - 1].width(b.index()));
    }
  }
}

/// @}

private:

/// Histograms
HistoGroupPtr<double, string> _h_ET;
vector<YODA::Axis<double>> _etaxes;
vector<vector<string>> _edges;

};

RIVET_DECLARE_ALIASED_PLUGIN(CDF_2001_I538041, CDF_2001_S4517016);

} ```

Aliases: - CDF_2001_S4517016