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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
No authors listed References:
  • Phys. Rev., D23(1981), 604-633
  • DOI: 10.1103/PhysRevD.23.604
Beams: p+ p+
Beam energies: (13.7, 13.7) GeV
    No run details 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
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5#include "Rivet/Projections/DileptonFinder.hh"
  6
  7namespace Rivet {
  8
  9
 10  /// Measurement of dimuon continuum in proton-nucleus collisions
 11  class E288_1981_I153009 : public Analysis {
 12  public:
 13
 14    /// Constructor
 15    RIVET_DEFAULT_ANALYSIS_CTOR(E288_1981_I153009);
 16
 17
 18    /// @name Analysis methods
 19    /// @{
 20
 21    /// Book histograms and initialise projections before the run
 22    void init() {
 23
 24      // Initialise and register projections
 25      DileptonFinder zfinder(91.2*GeV, 0.0, Cuts::abseta < 15.0 && Cuts::abspid == PID::MUON, Cuts::massIn(3.5*GeV, 30.0*GeV));
 26      declare(zfinder, "DileptonFinder");
 27
 28      // Book histograms
 29      // 400 GeV and y = 0.03
 30      book(_hist_pT_M_400, {5., 6., 7., 8., 9., 10., 11., 12., 13., 14.});
 31      for (auto& b : _hist_pT_M_400->bins()) {
 32        book(b, 9, 1, b.index());
 33      }
 34
 35      int Nbin = 50;
 36      book(_h_m_DiMuon,  "DiMuon_mass", Nbin, 0.0,30.0);
 37      book(_h_pT_DiMuon, "DiMuon_pT",   Nbin, 0.0,20.0);
 38      book(_h_y_DiMuon,  "DiMuon_y",    Nbin,-8.0, 8.0);
 39      book(_h_xF_DiMuon, "DiMuon_xF",   Nbin,-1.5, 1.5);
 40    }
 41
 42
 43    /// Perform the per-event analysis
 44    void analyze(const Event& event) {
 45
 46      const double sqrts_tol = 10. ;
 47      if (!isCompatibleWithSqrtS(27.4*GeV, sqrts_tol)) {
 48        MSG_ERROR("Incorrect beam energy used: " << sqrtS()/GeV);
 49        throw Error("Unexpected sqrtS ! Only 27.4 GeV is supported");
 50      }
 51
 52      const DileptonFinder& zfinder = apply<DileptonFinder>(event, "DileptonFinder");
 53      if (zfinder.particles().size() >= 1) {
 54
 55        double Zmass = zfinder.bosons()[0].momentum().mass()/GeV;
 56        double Zpt   = zfinder.bosons()[0].momentum().pT()/GeV;
 57        double Zpl   = zfinder.bosons()[0].momentum().pz()/GeV;
 58        double Zy    = zfinder.bosons()[0].momentum().rapidity();
 59        //double ZE    = zfinder.bosons()[0].momentum().E();
 60
 61        double xf = 2.*Zpl/sqrtS() ;
 62        _h_xF_DiMuon->fill(xf);
 63        _h_m_DiMuon->fill(Zmass/GeV);
 64        _h_pT_DiMuon->fill(Zpt);
 65        _h_y_DiMuon ->fill(Zy);
 66        double Zymin = -1.0;
 67        double Zymax = 1.03;
 68        double Z_y_width = Zymax - Zymin ;
 69        if ( Zy > Zymin && Zy < Zymax ) {
 70          // Edsigma^3/dp^3 = 2E/(pi*sqrts)dsigma/dx_F/dq_T^2 = 1/pi dsigma/dy/dq_T^2
 71          // normalisation of Zy bin width = Zwidth
 72          if (Zpt > 0) _hist_pT_M_400->fill(Zmass,Zpt, 1./2./Zpt/Z_y_width);
 73        }
 74      }
 75
 76    }
 77
 78
 79    /// Normalise histograms etc., after the run
 80    void finalize() {
 81      scale(_hist_pT_M_400, crossSection()/femtobarn/(sumOfWeights() * M_PI));
 82    }
 83
 84    /// @}
 85
 86
 87    /// @name Histograms
 88    /// @{
 89    Histo1DGroupPtr _hist_pT_M_400;
 90    Histo1DPtr _h_m_DiMuon ;
 91    Histo1DPtr _h_pT_DiMuon;
 92    Histo1DPtr _h_y_DiMuon;
 93    Histo1DPtr _h_xF_DiMuon;
 94    /// @}
 95
 96  };
 97
 98
 99  RIVET_DECLARE_PLUGIN(E288_1981_I153009);
100
101}