Rivet analyses

title: E288_1981_I153009

Measurement of the continuum of dimuons produced in high-energy proton-nucleus collisions

Experiment: E288 (Fermilab p-N)

Inspire ID: 153009

Status: VALIDATED

Authors: none listed

References: - Phys. Rev., D23(1981), 604-633 - DOI: 10.1103/PhysRevD.23.604

Beams: p+ p+

Beam energies: (13.7, 13.7)GeV

Run details: none listed

We report final results of a series of measurements of continuum dimuon production in proton-nucleus collisions at Fermilab. New results with 6 times more statistics are included.

Source code:E288_1981_I153009.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DileptonFinder.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/FinalState.hh"

namespace Rivet {

/// Measurement of dimuon continuum in proton-nucleus collisions class E288_1981_I153009 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(E288_1981_I153009);


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

/// Book histograms and initialise projections before the run
void init() {

  // Initialise and register projections
  DileptonFinder zfinder(91.2 * GeV, 0.0, Cuts::abseta < 15.0 && Cuts::abspid == PID::MUON,
                         Cuts::massIn(3.5 * GeV, 30.0 * GeV));
  declare(zfinder, "DileptonFinder");

  // Book histograms
  // 400 GeV and y = 0.03
  book(_hist_pT_M_400, {5., 6., 7., 8., 9., 10., 11., 12., 13., 14.});
  for (auto& b : _hist_pT_M_400->bins()) {
    book(b, 9, 1, b.index());
  }

  int Nbin = 50;
  book(_h_m_DiMuon, "DiMuon_mass", Nbin, 0.0, 30.0);
  book(_h_pT_DiMuon, "DiMuon_pT", Nbin, 0.0, 20.0);
  book(_h_y_DiMuon, "DiMuon_y", Nbin, -8.0, 8.0);
  book(_h_xF_DiMuon, "DiMuon_xF", Nbin, -1.5, 1.5);
}


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

  const DileptonFinder& zfinder = apply<DileptonFinder>(event, "DileptonFinder");
  if (zfinder.particles().size() >= 1) {

    double Zmass = zfinder.bosons()[0].momentum().mass() / GeV;
    double Zpt = zfinder.bosons()[0].momentum().pT() / GeV;
    double Zpl = zfinder.bosons()[0].momentum().pz() / GeV;
    double Zy = zfinder.bosons()[0].momentum().rapidity();
    //double ZE    = zfinder.bosons()[0].momentum().E();

    double xf = 2. * Zpl / sqrtS();
    _h_xF_DiMuon->fill(xf);
    _h_m_DiMuon->fill(Zmass / GeV);
    _h_pT_DiMuon->fill(Zpt);
    _h_y_DiMuon->fill(Zy);
    double Zymin = -1.0;
    double Zymax = 1.03;
    double Z_y_width = Zymax - Zymin;
    if (Zy > Zymin && Zy < Zymax) {
      // Edsigma^3/dp^3 = 2E/(pi*sqrts)dsigma/dx_F/dq_T^2 = 1/pi dsigma/dy/dq_T^2
      // normalisation of Zy bin width = Zwidth
      if (Zpt > 0) _hist_pT_M_400->fill(Zmass, Zpt, 1. / 2. / Zpt / Z_y_width);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_hist_pT_M_400, crossSection() / femtobarn / (sumOfWeights() * M_PI));
}

/// @}


/// @name Histograms
/// @{
Histo1DGroupPtr _hist_pT_M_400;
Histo1DPtr _h_m_DiMuon;
Histo1DPtr _h_pT_DiMuon;
Histo1DPtr _h_y_DiMuon;
Histo1DPtr _h_xF_DiMuon;
/// @}

};

RIVET_DECLARE_PLUGIN(E288_1981_I153009);

} ```