Rivet analyses

title: LHCB_2014_I1309880

Mass distributions in $B_c^+\to J/\psi p\bar{p}\pi^+$

Experiment: LHCB (LHC)

Inspire ID: 1309880

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 113 (2014) 15, 152003

Beams: * *

Beam energies: ANY

Run details: - Any process producing B_c+, originally pp

Mass distributions in $B_c^+\to J/\psi p\bar{p}\pi^+$. The data were extracted from the plots in the paper and may not be corrected for efficiency and acceptance.

Source code:LHCB_2014_I1309880.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B_c -> J/psi p pbar pi+ class LHCB_2014_I1309880 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2014_I1309880);


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

/// Book histograms and initialise projections before the run
void init() {
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 541);
  declare(ufs, "UFS");
  DecayedParticles BC(ufs);
  BC.addStable(PID::PI0);
  BC.addStable(PID::K0S);
  BC.addStable(PID::JPSI);
  declare(BC, "BC");
  for (unsigned int ix = 0; ix < 2; ++ix) book(_h[ix], 1, 1, 1 + ix);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode = {{443, 1}, {2212, 1}, {2212, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& modeCC = {{443, 1}, {2212, 1}, {2212, 1}, {-211, 1}};
  DecayedParticles BC = apply<DecayedParticles>(event, "BC");
  // loop over particles
  for (unsigned int ix = 0; ix < BC.decaying().size(); ++ix) {
    int sign = BC.decaying()[ix].pid() / BC.decaying()[ix].abspid();
    if ((sign == 1 && BC.modeMatches(ix, 4, mode)) || (sign == -1 && BC.modeMatches(ix, 4, modeCC))) {
      const Particle& prot = BC.decayProducts()[ix].at(sign * 2212)[0];
      const Particle& pbar = BC.decayProducts()[ix].at(-sign * 2212)[0];
      const Particle& pip = BC.decayProducts()[ix].at(sign * 211)[0];
      _h[0]->fill((prot.momentum() + pbar.momentum()).mass());
      _h[1]->fill((prot.momentum() + pip.momentum()).mass());
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 2; ++ix) normalize(_h[ix], 1., false);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[2];
/// @}

};

RIVET_DECLARE_PLUGIN(LHCB_2014_I1309880);

} ```