Rivet analyses

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"

namespace Rivet {


  /// Ratio of energy in -6.6 < eta < -5.2 for events with a charged-particle jet
  class CMS_2013_I1218372 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2013_I1218372);


    void init() {

      // gives the range of eta and min pT for the final state from which I get the jets
      FastJets jetpro(ChargedFinalState(Cuts::abseta < 2.5 && Cuts::pT >= 0.3 * GeV), JetAlg::ANTIKT, 0.5);
      declare(jetpro, "Jets");

      // skip Neutrinos and Muons
      VetoedFinalState fsv(FinalState(Cuts::etaIn(-7.0, -4.0)));
      fsv.vetoNeutrinos();
      fsv.addVetoPairId(PID::MUON);
      declare(fsv, "fsv");

      // for the hadron level selection
      VetoedFinalState sfsv;
      sfsv.vetoNeutrinos();
      sfsv.addVetoPairId(PID::MUON);
      declare(sfsv, "sfsv");

      size_t id = 0;
      for (double eVal : allowedEnergies()) {
        const string en = toString(round(eVal));
        if (isCompatibleWithSqrtS(eVal)) _sqs = en;
        ++id;

        //counters
        book(_c[en + "pass"], "_pass" + en);
        book(_c[en + "incl"], "_incl" + en);

        // Temporary histograms to fill the energy flow for leading jet events.
        // Ratios are calculated in finalize().
        book(_e[en + "ratio"], id, 1, 1);
        book(_h[en + "num"], "TMP/eflow_jet" + en, refData(id, 1, 1));  // Leading jet energy flow in pt
        book(_h[en + "den"], "TMP/number_jet" + en, refData(id, 1, 1)); // Number of events in pt
      }
      raiseBeamErrorIf(_sqs.empty());
    }


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

      // Skip if the event is empty
      const FinalState& fsv = apply<FinalState>(event, "fsv");
      if (fsv.empty()) vetoEvent;

      // ====================== Minimum Bias selection

      const FinalState& sfsv = apply<FinalState>(event, "sfsv");
      Particles parts = sfsv.particles(cmpMomByRap);
      if (parts.empty()) vetoEvent;

      // find dymax
      double dymax = 0;
      int gap_pos = -1;
      for (size_t i = 0; i < parts.size() - 1; ++i) {
        double dy = parts[i + 1].rap() - parts[i].rap();
        if (dy > dymax) {
          dymax = dy;
          gap_pos = i;
        }
      }

      // calculate mx2 and my2
      FourMomentum xmom;
      for (int i = 0; i <= gap_pos; ++i) {
        xmom += parts[i].mom();
      }
      double mx2 = xmom.mass2();
      if (mx2 < 0) vetoEvent;

      FourMomentum ymom;
      for (size_t i = gap_pos + 1; i < parts.size(); ++i) {
        ymom += parts[i].mom();
      }
      double my2 = ymom.mass2();
      if (my2 < 0) vetoEvent;

      // calculate xix and xiy and xidd
      double xix = mx2 / sqr(sqrtS());
      double xiy = my2 / sqr(sqrtS());
      double xidd = mx2 * my2 / sqr(sqrtS() * 0.938 * GeV);

      // combine the selection: xi cuts
      bool passedHadronCuts = false;
      if (_sqs == "900"s && (xix > 0.1 || xiy > 0.4 || xidd > 0.5)) passedHadronCuts = true;
      if (_sqs == "2760"s && (xix > 0.07 || xiy > 0.2 || xidd > 0.5)) passedHadronCuts = true;
      if (_sqs == "7000"s && (xix > 0.04 || xiy > 0.1 || xidd > 0.5)) passedHadronCuts = true;
      if (!passedHadronCuts) vetoEvent;

      //  ============================== MINIMUM BIAS EVENTS

      // loop over particles to calculate the energy
      _c[_sqs + "pass"]->fill();

      for (const Particle& p : fsv.particles()) {
        if (-5.2 > p.eta() && p.eta() > -6.6) _c[_sqs + "incl"]->fill(p.E() / GeV);
      }

      //  ============================== JET EVENTS

      const FastJets& jetpro = apply<FastJets>(event, "Jets");
      const Jets& jets = jetpro.jetsByPt(Cuts::pT > 1.0 * GeV);
      if (jets.size() < 1) vetoEvent;

      if (jets[0].abseta() < 2.0) {
        _h[_sqs + "den"]->fill(jets[0].pT() / GeV);

        // energy flow
        for (const Particle& p : fsv.particles()) {
          if (p.eta() > -6.6 && p.eta() < -5.2) { // ask for the CASTOR region
            _h[_sqs + "num"]->fill(jets[0].pT() / GeV, p.E() / GeV);
          }
        }
      }

    } // analysis

    void finalize() {
      for (double eVal : allowedEnergies()) {
        const string en = toString(round(eVal));
        if (_c[en + "incl"]->sumW()) scale(_h[en + "num"], *_c[en + "pass"] / *_c[en + "incl"]);
        divide(_h[en + "num"], _h[en + "den"], _e[en + "ratio"]);
      }
    }

  private:

    // counters
    map<string, CounterPtr> _c;
    map<string, Histo1DPtr> _h;
    map<string, Estimate1DPtr> _e;

    string _sqs = "";
  };


  RIVET_DECLARE_PLUGIN(CMS_2013_I1218372);

}