Rivet analyses

Transverse momentum spectra of pions, kaons and protons in pp collisions at 7 TeV

Experiment: ALICE (LHC)

Inspire ID: 1357424

Status: VALIDATED

Authors: - Andreas Morsch

References: - Eur.Phys.J.C 75 (2015) 5, 226 - arXiv: 1504.00024

Beams: p+ p+

Beam energies: (3500.0, 3500.0)GeV

Run details: - Inelastic pp collisions at sqrt(s) = 7 TeV

Obtaining the transverse momentum spectra of primary pions, kaons and protons in pp collisions at $\sqrt{s} = 7$ TeV with ALICE at the LHC. K/pi and p/pi ratios are also included.

Source code:ALICE_2015_I1357424.cc

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {


  class ALICE_2015_I1357424 : public Analysis {
  public:

    ALICE_2015_I1357424()
        : Analysis("ALICE_2015_I1357424") { }


  public:

    void init() {
      const ChargedFinalState cfs(Cuts::absrap < 0.5);
      declare(cfs, "CFS");
      //
      // plots from the paper
      book(_histPtPions, "d01-x01-y01");   // pions
      book(_histPtKaons, "d01-x01-y02");   // kaons
      book(_histPtProtons, "d01-x01-y03"); // protons
      book(_histPtKtoPi, "d02-x01-y01");   // K to pi ratio
      book(_histPtPtoPi, "d03-x01-y01");   // p to pi ratio
      //
      // temp histos for ratios
      book(_histPtPionsR1, "TMP/pT_pi1",
           refData(2, 1, 1)); // pi histo compatible with more restricted kaon binning
      book(_histPtPionsR2, "TMP/pT_pi2",
           refData(3, 1, 1)); // pi histo compatible with more restricted proton binning
      book(_histPtKaonsR, "TMP/pT_K", refData(2, 1, 1));   // K histo with more restricted binning
      book(_histPtProtonsR, "TMP/pT_p", refData(3, 1, 1)); // p histo with more restricted binning
    }


    void analyze(const Event& event) {
      const ChargedFinalState& cfs = apply<ChargedFinalState>(event, "CFS");
      for (const Particle& p : cfs.particles()) {
        // protections against mc generators decaying long-lived particles
        if (!(p.hasAncestorWith(Cuts::pid == 310) || p.hasAncestorWith(Cuts::pid == -310) ||   // K0s
              p.hasAncestorWith(Cuts::pid == 130) || p.hasAncestorWith(Cuts::pid == -130) ||   // K0l
              p.hasAncestorWith(Cuts::pid == 3322) || p.hasAncestorWith(Cuts::pid == -3322) || // Xi0
              p.hasAncestorWith(Cuts::pid == 3122) || p.hasAncestorWith(Cuts::pid == -3122) || // Lambda
              p.hasAncestorWith(Cuts::pid == 3222) || p.hasAncestorWith(Cuts::pid == -3222) || // Sigma+/-
              p.hasAncestorWith(Cuts::pid == 3312) || p.hasAncestorWith(Cuts::pid == -3312) || // Xi-/+
              p.hasAncestorWith(Cuts::pid == 3334) || p.hasAncestorWith(Cuts::pid == -3334)))  // Omega-/+
        {
          switch (abs(p.pid())) {
            case 211: // pi+
              _histPtPions->fill(p.pT() / GeV);
              _histPtPionsR1->fill(p.pT() / GeV);
              _histPtPionsR2->fill(p.pT() / GeV);
              break;
            case 2212: // proton
              _histPtProtons->fill(p.pT() / GeV);
              _histPtProtonsR->fill(p.pT() / GeV);
              break;
            case 321: // K+
              _histPtKaons->fill(p.pT() / GeV);
              _histPtKaonsR->fill(p.pT() / GeV);
              break;
          } // particle switch
        } // primary pi, K, p only
      } // particle loop
    }

    void finalize() {
      divide(_histPtKaonsR, _histPtPionsR1, _histPtKtoPi);
      divide(_histPtProtonsR, _histPtPionsR2, _histPtPtoPi);

      scale(_histPtPions, 1. / sumOfWeights());
      scale(_histPtProtons, 1. / sumOfWeights());
      scale(_histPtKaons, 1. / sumOfWeights());
    }


  private:

    Histo1DPtr _histPtPions;
    Histo1DPtr _histPtProtons;
    Histo1DPtr _histPtKaons;

    Histo1DPtr _histPtPionsR1;
    Histo1DPtr _histPtPionsR2;
    Histo1DPtr _histPtProtonsR;
    Histo1DPtr _histPtKaonsR;

    Estimate1DPtr _histPtKtoPi;
    Estimate1DPtr _histPtPtoPi;
  };


  RIVET_DECLARE_PLUGIN(ALICE_2015_I1357424);

}