Rivet analyses

title: CDF_2009_I834437

Measurement of the inclusive isolated prompt photon cross-section

Experiment: CDF (Tevatron Run 2)

Inspire ID: 834437

Status: VALIDATED

Authors: - Frank Siegert

References: - arXiv: 0910.3623

Beams: p- p+

Beam energies: (980.0, 980.0)GeV

Run details: - $\gamma$ + jet processes in ppbar collisions at $\sqrt{s} = 1960$~GeV. Minimum pT cut on the photon in the analysis is 30~GeV.

A measurement of the cross section for the inclusive production of isolated photons. The measurement covers the pseudorapidity region $|\eta^\gamma|<1.0$ and the transverse energy range $E_T^\gamma>30$~GeV and is based on 2.5~fb$^{-1}$ of integrated luminosity. The cross section is measured differential in $E_\perp(\gamma)$.

Source code:CDF_2009_I834437.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/FinalState.hh"

include "Rivet/Projections/LeadingParticlesFinalState.hh"

namespace Rivet {

/// @brief CDF inclusive isolated prompt photon cross-section class CDF_2009_I834437 : public Analysis { public:

RIVET_DEFAULT_ANALYSIS_CTOR(CDF_2009_I834437);


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

/// Book histograms and initialise projections before the run
void init() {
  FinalState fs;
  declare(fs, "FS");

  LeadingParticlesFinalState photonfs(FinalState((Cuts::etaIn(-1.0, 1.0) && Cuts::pT >= 30.0 * GeV)));
  photonfs.addParticleId(PID::PHOTON);
  declare(photonfs, "LeadingPhoton");

  book(_h_Et_photon, 1, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  Particles fs = apply<FinalState>(event, "FS").particles();
  Particles photons = apply<LeadingParticlesFinalState>(event, "LeadingPhoton").particles();
  if (photons.size() != 1) {
    vetoEvent;
  }
  FourMomentum leadingPhoton = photons[0].momentum();
  double eta_P = leadingPhoton.eta();
  double phi_P = leadingPhoton.phi();
  FourMomentum mom_in_cone;
  for (const Particle& p : fs) {
    if (deltaR(eta_P, phi_P, p.eta(), p.phi()) < 0.4) {
      mom_in_cone += p.momentum();
    }
  }
  if ((mom_in_cone.Et() - leadingPhoton.Et()) > 2.0 * GeV) {
    vetoEvent;
  }
  _h_Et_photon->fill(leadingPhoton.Et());
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_Et_photon, crossSection() / picobarn / sumOfWeights() / 2.0);
}

/// @}

private:

/// Histogram
Histo1DPtr _h_Et_photon;

};

RIVET_DECLARE_ALIASED_PLUGIN(CDF_2009_I834437, CDF_2009_S8436959);

} ```

Aliases: - CDF_2009_S8436959