Rivet analyses

Forward charged particle pseudorapidity density in pp collisions at $\sqrt{s} = 8 \TeV$ using a displaced interaction point

Experiment: TOTEM (LHC)

Inspire ID: 1328627

Status: VALIDATED

Authors: - Sercan Sen

References: - EPJ C75,126 - CERN-PH-EP-2014-260 - arXiv: 1411.4963

Beams: p+ p+

Beam energies: (4000.0, 4000.0)GeV

Run details: - pp QCD interactions at 8 TeV.

The pseudorapidity density of charged particles dNch/dη is measured by the TOTEM experiment in pp collisions at $\sqrt{s} = 8$ TeV within the ranges 3.9 < η < 4.7 and −6.95 < η < −6.9. Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25,m from the nominal interaction point. The data sample is expected to include 96–97% of the inelastic proton–proton interactions. The measurement reported here considers charged particles with pT > 0 MeV/c, produced in inelastic interactions with at least one charged particle in −7 < η < −6 or 3.7 < η < 4.8. The dNch/dη has been found to decrease with |η|, from 5.11 ± 0.73 at η = 3.95 to 1.81 ± 0.56 at η = −6.925.

Source code:TOTEM_2014_I1328627.cc

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

namespace Rivet {


  class TOTEM_2014_I1328627 : public Analysis {
  public:


    RIVET_DEFAULT_ANALYSIS_CTOR(TOTEM_2014_I1328627);



    void init() {
      ChargedFinalState cfsm(Cuts::etaIn(-7.0, -6.0));
      ChargedFinalState cfsp(Cuts::etaIn( 3.7,  4.8));
      declare(cfsm, "CFSM");
      declare(cfsp, "CFSP");

      book(_h_eta ,1, 1, 1);
      book(_sumofweights, "sumofweights");
    }


    void analyze(const Event& event) {
      const ChargedFinalState cfsm = apply<ChargedFinalState>(event, "CFSM");
      const ChargedFinalState cfsp = apply<ChargedFinalState>(event, "CFSP");
      if (cfsm.size() == 0 && cfsp.size() == 0) vetoEvent;

      _sumofweights->fill();
      for (const Particle& p : cfsm.particles() + cfsp.particles()) {
        _h_eta->fill(p.abseta());
      }
    }


    void finalize() {
      scale(_h_eta, 1./ *_sumofweights);
    }


  private:

    CounterPtr _sumofweights;
    Histo1DPtr _h_eta;

  };


  RIVET_DECLARE_PLUGIN(TOTEM_2014_I1328627);


}