Rivet analyses

title: ATLAS_2011_I882984

Jet shapes at 7 TeV in ATLAS

Experiment: ATLAS (LHC)

Inspire ID: 882984

Status: VALIDATED

Authors: - Andy Buckley - Francesc Vives - Judith Katzy

References: - Expt page: ATLAS-STDM-2010-10 - arXiv: 1101.0070

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - $pp$ QCD interactions at 7 TeV GeV, corresponding to JX samples. Matching plots to kinematic $\pT$ cut samples, or merging from slices or $\pT$-enhanced sampling is advised.

Measurement of jet shapes in inclusive jet production in $pp$ collisions at 7 TeV based on 3 pb$^{-1}$ of data. Jets are reconstructed in $|\eta| < 5$ using the anti-$k_\perp$ algorithm with $30 < \pT < 600$ GeV and $|y| < 2.8$.

Source code:ATLAS_2011_I882984.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/JetShape.hh"

include "Rivet/Projections/VetoedFinalState.hh"

include "Rivet/Projections/VisibleFinalState.hh"

namespace Rivet {

/// @brief ATLAS jet shape analysis /// @author Andy Buckley, Judith Katzy, Francesc Vives class ATLAS_2011_I882984 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2011_I882984);


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

void init() {
  // Set up projections
  const FinalState fs((Cuts::etaIn(-5.0, 5.0)));
  declare(fs, "FS");
  FastJets fj(fs, JetAlg::ANTIKT, 0.6);
  fj.useInvisibles();
  declare(fj, "Jets");

  // Specify pT bins
  _ptedges = {{30.0, 40.0, 60.0, 80.0, 110.0, 160.0, 210.0, 260.0, 310.0, 400.0, 500.0, 600.0}};
  _yedges = {{0.0, 0.3, 0.8, 1.2, 2.1, 2.8}};

  // Register a jet shape projection and histogram for each pT bin
  for (size_t i = 0; i < 11; ++i) {
    for (size_t j = 0; j < 6; ++j) {
      if (i == 8 && j == 4) continue;
      if (i == 9 && j == 4) continue;
      if (i == 10 && j != 5) continue;

      // Set up projections for each (pT,y) bin
      _jsnames_pT[i][j] = "JetShape" + to_str(i) + to_str(j);
      const double ylow = (j < 5) ? _yedges[j] : _yedges.front();
      const double yhigh = (j < 5) ? _yedges[j + 1] : _yedges.back();
      const JetShape jsp(fj, 0.0, 0.7, 7, _ptedges[i], _ptedges[i + 1], ylow, yhigh, RAPIDITY);
      declare(jsp, _jsnames_pT[i][j]);

      // Book profile histograms for each (pT,y) bin
      book(_profhistRho_pT[i][j], i + 1, j + 1, 1);
      book(_profhistPsi_pT[i][j], i + 1, j + 1, 2);
    }
  }
}


/// Do the analysis
void analyze(const Event& evt) {

  // Get jets and require at least one to pass pT and y cuts
  const Jets jets = apply<FastJets>(evt, "Jets")
                        .jetsByPt(Cuts::ptIn(_ptedges.front() * GeV, _ptedges.back() * GeV)
                                  && Cuts::absrap < 2.8);
  MSG_DEBUG("Jet multiplicity before cuts = " << jets.size());
  if (jets.size() == 0) {
    MSG_DEBUG("No jets found in required pT and rapidity range");
    vetoEvent;
  }
  // Calculate and histogram jet shapes
  for (size_t ipt = 0; ipt < 11; ++ipt) {
    for (size_t jy = 0; jy < 6; ++jy) {
      if (ipt == 8 && jy == 4) continue;
      if (ipt == 9 && jy == 4) continue;
      if (ipt == 10 && jy != 5) continue;
      const JetShape& jsipt = apply<JetShape>(evt, _jsnames_pT[ipt][jy]);
      for (size_t ijet = 0; ijet < jsipt.numJets(); ++ijet) {
        for (size_t rbin = 0; rbin < jsipt.numBins(); ++rbin) {
          const double r_rho = jsipt.rBinMid(rbin);
          _profhistRho_pT[ipt][jy]->fill(r_rho, (1. / 0.1) * jsipt.diffJetShape(ijet, rbin));
          const double r_Psi = jsipt.rBinMid(rbin);
          _profhistPsi_pT[ipt][jy]->fill(r_Psi, jsipt.intJetShape(ijet, rbin));
        }
      }
    }
  }
}

/// @}

private:

/// @name Analysis data
/// @{

/// Jet \f$ p_\perp\f$ bins.
vector<double> _ptedges; // This can't be a raw array if we want to initialise it non-painfully
vector<double> _yedges;

/// JetShape projection name for each \f$p_\perp\f$ bin.
string _jsnames_pT[11][6];

///@}


/// @name Histograms
/// @{
Profile1DPtr _profhistRho_pT[11][6];
Profile1DPtr _profhistPsi_pT[11][6];
/// @}

};

RIVET_DECLARE_ALIASED_PLUGIN(ATLAS_2011_I882984, ATLAS_2011_S8924791);

} ```

Aliases: - ATLAS_2011_S8924791