Rivet analyses

title: LHCB_2017_I1630633

$B^\pm$ meson production at 7 and 13 TeV

Experiment: LHCB (LHC)

Inspire ID: 1630633

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - JHEP 12 (2017) 026

Beams: p+ p+

Beam energies: (3500.0, 3500.0); (6500.0, 6500.0)GeV

Run details: - hadronic events with B+ mesons

Measurement of the double differential (in $p_\perp$ and $y$) cross section for $B^\pm$ meson production at 7 and 13 TeV by the LHCb collaboration.

Source code:LHCB_2017_I1630633.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B+ cross section at 7 and 13 TeV class LHCB_2017_I1630633 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2017_I1630633);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(UnstableParticles(), "UFS");
  for (double eVal : allowedEnergies()) {
    const int en = int(eVal + 0.5);
    if (isCompatibleWithSqrtS(eVal)) _sqs = en;

    int ih(en == 13000);
    book(_h_B[en], {2.0, 2.5, 3.0, 3.5, 4.0, 4.5});
    for (auto& b : _h_B[en]->bins()) {
      book(b, 1 + ih, 1, b.index());
    }
    book(_h_pT[en], 3, 1, 1 + ih);
    book(_h_y[en], 4, 1, 1 + ih);
  }
  raiseBeamErrorIf(_sqs == 0);
}


/// 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 == 521)) {
    double absrap = p.absrap();
    if (absrap < 2. || absrap > 4.5) continue;
    double pT = p.pT();
    if (pT > 40. * GeV) continue;
    _h_B[_sqs]->fill(absrap, pT / GeV);
    _h_pT[_sqs]->fill(pT / GeV);
    _h_y[_sqs]->fill(absrap);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // 1/2 due rapidity folding +/-
  const double factor = 0.5 * crossSection() / nanobarn / sumOfWeights();
  scale(_h_B, factor);
  divByGroupWidth(_h_B);
  scale(_h_pT, factor);
  scale(_h_y, factor / 1000.);
}

/// @}


/// @name Histograms
/// @{
map<int, Histo1DGroupPtr> _h_B;
map<int, Histo1DPtr> _h_pT, _h_y;
int _sqs = 0;
/// @}

};

RIVET_DECLARE_PLUGIN(LHCB_2017_I1630633);

} ```