Rivet analyses

title: LHCB_2013_I1238809

B meson production at 7 TeV

Experiment: LHCB (LHC)

Inspire ID: 1238809

Status: VALIDATED

Authors: - Peter Richardson

References: - JHEP 08 (2013) 117

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - hadronic events with B meson

Measurement of the double differential (in $p_\perp$ and $y$) cross section for B meson production at 7 TeV by the LHCb collaboration.

Source code:LHCB_2013_I1238809.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B meson production at 7 TeV class LHCB_2013_I1238809 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2013_I1238809);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(UnstableParticles(), "UFS");
  for (unsigned int ib = 0; ib < 3; ++ib) {
    book(_h_sigma[ib], 1, 1, 1 + ib);
    book(_h_pT[ib], 5 + ib, 1, 1);
    book(_h_y[ib], 8 + ib, 1, 1);
    book(_h_B[ib], {2.0, 2.5, 3.0, 3.5, 4.0, 4.5});
    for (unsigned int iy = 0; iy < 5; ++iy) {
      book(_h_B[ib]->bin(iy + 1), 2 + ib, 1, 1 + iy);
    }
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // Final state of unstable particles to get particle spectra
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  for (const Particle& p : ufs.particles(Cuts::pid == 511 or Cuts::pid == 521 or Cuts::pid == 531)) {
    double absrap = p.absrap();
    if (absrap < 2. || absrap > 4.5) continue;
    unsigned int ib = (p.pid() % 100) / 10 - 1;
    double pT = p.perp();
    if (pT > 40.) continue;
    _h_sigma[ib]->fill(round(sqrtS()));
    _h_B[ib]->fill(absrap, pT);
    _h_pT[ib]->fill(pT);
    _h_y[ib]->fill(absrap);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // 1/2 due rapidity folding +/-
  double factor = 0.5 * crossSection() / microbarn / sumOfWeights();
  for (unsigned int ib = 0; ib < 3; ++ib) {
    scale(_h_B[ib], factor);
    divByGroupWidth(_h_B[ib]);
    scale(_h_sigma[ib], factor);
    scale(_h_y[ib], factor);
    scale(_h_pT[ib], factor);
  }
}

/// @}


/// @name Histograms
/// @{
BinnedHistoPtr<int> _h_sigma[3];
Histo1DGroupPtr _h_B[3];
Histo1DPtr _h_pT[3], _h_y[3];
/// @}

};

RIVET_DECLARE_PLUGIN(LHCB_2013_I1238809);

} ```