## main102

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    // mai102.cc is a part of the PYTHIA event generator.
    // Copyright (C) 2025 Torbjorn Sjostrand.
    // PYTHIA is licenced under the GNU GPL v2 or later, see COPYING for details.
    // Please respect the MCnet Guidelines, see GUIDELINES for details.

    // Keywords:
    //            Basic usage
    //            Z production
    //            Tevatron

    // This is a simple test program. It fits on one slide in a talk.
    // It studies the pT_Z spectrum at the Tevatron.

    #include "Pythia8/Pythia.h"
    using namespace Pythia8;
    int main() {
      // Generator. Process selection. Tevatron initialization. Histogram.
      Pythia pythia;
      pythia.readString("Beams:idB = -2212");
      pythia.readString("Beams:eCM = 1960.");
      pythia.readString("WeakSingleBoson:ffbar2gmZ = on");
      pythia.readString("PhaseSpace:mHatMin = 80.");
      pythia.readString("PhaseSpace:mHatMax = 120.");
      // If Pythia fails to initialize, exit with error.
      if (!pythia.init()) return 1;
      Hist pTZ("dN/dpTZ", 100, 0., 100.);
      // Begin event loop. Generate event. Skip if error. List first one.
      for (int iEvent = 0; iEvent < 1000; ++iEvent) {
        if (!pythia.next()) continue;
        // Loop over particles in event. Find last Z0 copy. Fill its pT.
        int iZ = 0;
        for (int i = 0; i < pythia.event.size(); ++i)
          if (pythia.event[i].id() == 23) iZ = i;
        pTZ.fill( pythia.event[iZ].pT() );
      // End of event loop. Statistics. Histogram. Done.
      }
      pythia.stat();
      cout << pTZ;
      return 0;
    }