Rivet analyses

title: TPC_1988_I262143

Charged particle spectra at 29 GeV

Experiment: TPC (PEP)

Inspire ID: 262143

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 61 (1988) 1263, 1988

Beams: e+ e-

Beam energies: (14.5, 14.5)GeV

Run details: - e+e- to hadrons at 29 GeV

Momentum spectra for all charged particles, $\pi^\pm$, $K^\pm$ $p,\bar{p}$ in $e^+e^-$ collisions at 29 GeV measured by the TPC experiment.

Source code:TPC_1988_I262143.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/Beam.hh"

include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {

/// @brief Add a short analysis description here class TPC_1988_I262143 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(TPC_1988_I262143);


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

/// Book histograms and initialise projections before the run
void init() {
  declare(Beam(), "Beams");
  declare(ChargedFinalState(), "FS");

  // Book histograms
  book(_h["z_pi"], 1, 1, 1);
  book(_h["z_K"], 1, 1, 2);
  book(_h["z_p"], 1, 1, 3);
  book(_h["z_all"], 1, 1, 4);

  book(_h["z2_pi"], 5, 1, 1);
  book(_h["z2_K"], 5, 1, 2);
  book(_h["z2_p"], 5, 1, 3);

  tribook("pi", 6, 1, 1);
  tribook("K", 6, 1, 2);
  tribook("p", 6, 1, 3);
  tribook("2_K", 7, 1, 1);
  tribook("2_p", 7, 1, 2);
  tribook("3_p", 7, 1, 3);
}

void tribook(const string& label, unsigned int d, unsigned int x, unsigned int y) {
  book(_nd["n_" + label], "TMP/n" + label, refData<YODA::BinnedEstimate<string>>(d, x, y));
  book(_nd["d_" + label], "TMP/d" + label, refData<YODA::BinnedEstimate<string>>(d, x, y));
  book(_ratio[label], d, x, y);
}

/// Perform the per-event analysis
void analyze(const Event& event) {

  if (_edges.empty()) {
    for (const auto& item : _ratio) {
      _edges[item.first] = _nd["n_" + item.first]->xEdges();
    }
  }
  // First, veto on leptonic events by requiring at least 4 charged FS particles
  const FinalState& fs = apply<FinalState>(event, "FS");
  const size_t numParticles = fs.particles().size();

  // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
  if (numParticles < 2) {
    MSG_DEBUG("Failed leptonic event cut");
    vetoEvent;
  }
  MSG_DEBUG("Passed leptonic event cut");

  // Get beams and average beam momentum
  const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
  const double meanBeamMom = (beams.first.p3().mod() + beams.second.p3().mod()) / 2.0;
  MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
  for (const Particle& p : fs.particles()) {
    double xP = p.p3().mod() / meanBeamMom;
    _h["z_all"]->fill(xP);
    histfill("d_pi", xP);
    histfill("d_K", xP);
    histfill("d_p", xP);
    int id = abs(p.pid());
    if (id == 211) {
      _h["z_pi"]->fill(xP);
      _h["z2_pi"]->fill(xP, xP);
      histfill("n_pi", xP, 100.);
      histfill("d_2_K", xP);
      histfill("d_2_p", xP);
      histfill("d_3_p", xP);
    }
    else if (id == 321) {
      _h["z_K"]->fill(xP);
      _h["z2_K"]->fill(xP, xP);
      histfill("n_K", xP, 100.);
      histfill("n_2_K", xP);
      histfill("d_3_p", xP);
    }
    else if (id == 2212) {
      _h["z_p"]->fill(xP);
      _h["z2_p"]->fill(xP, xP);
      histfill("n_p", xP, 100.);
      histfill("n_2_p", xP);
      histfill("n_3_p", xP);
    }
  }
}

/// Normalise histograms etc., after the run
void finalize() {
  scale(_h, 1. / sumOfWeights());
  for (auto& item : _ratio) {
    divide(_nd["n_" + item.first], _nd["d_" + item.first], item.second);
  }
}

/// @}

void histfill(const string& label, const double value, const double weight = 1.0) {
  string edge = "OTHER";
  const string tag = label.substr(2);
  size_t idx = _axis.index(value);
  if (tag == "pi") {
    if (0.035 <= value && value <= 0.07)
      idx -= 2;
    else if (0.09 <= value && value <= 0.11)
      idx -= 6;
    else if (0.16 <= value && value <= 0.7)
      idx -= 10;
    else
      idx = 0;
  }
  if (tag == "K") {
    if (0.035 <= value && value <= 0.07)
      idx -= 2;
    else if (0.09 <= value && value <= 0.14)
      idx -= 6;
    else if (0.25 <= value && value <= 0.7)
      idx -= 11;
    else
      idx = 0;
  }
  if (tag == "p" || tag == "2_p") {
    if (0.035 <= value && value <= 0.11)
      idx -= 2;
    else if (0.25 <= value && value <= 0.7)
      idx -= 10;
    else
      idx = 0;
  }
  if (tag == "2_K") {
    if (value <= 0.07)
      ;
    else if (0.09 <= value && value <= 0.11)
      idx -= 4;
    else if (0.25 <= value && value <= 0.7)
      idx -= 12;
    else
      idx = 0;
  }
  if (tag == "3_p") {
    if (0.035 <= value && value <= 0.07)
      idx -= 2;
    else if (0.09 <= value && value <= 0.11)
      idx -= 6;
    else if (0.25 <= value && value <= 0.7)
      idx -= 14;
    else
      idx = 0;
  }
  if (idx && idx <= _edges[tag].size()) edge = _edges[tag][idx - 1];
  _nd[label]->fill(edge, weight);
}


/// @name Histograms
/// @{
map<string, Histo1DPtr> _h;
map<string, BinnedHistoPtr<string>> _nd;
map<string, BinnedEstimatePtr<string>> _ratio;
map<string, vector<string>> _edges;
YODA::Axis<double> _axis{0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.06, 0.065, 0.07,
                         0.075, 0.08, 0.085, 0.09, 0.1,   0.11, 0.12,  0.13, 0.14, 0.16,  0.18,
                         0.2,   0.22, 0.25,  0.3,  0.35,  0.4,  0.5,   0.6,  0.7};


/// }

};

RIVET_DECLARE_PLUGIN(TPC_1988_I262143);

} ```