[Rivet] Z boson mass taken from ZFinder is pre-FSR or post-FSR

[Yu-hsiang Chang 張祐祥]

Hi all,
I have question for the FinalState and the ZFinder in Rivet. 
I want to know when I take the Z boson mass from the ZFinder, it is pre-FSR or post-FSR? (undergoes final state radiation(FSR) or not. In other words, does the 4-momentum of Z boson includes the energy and momentum of the FSR photon? ) For example, my Rivet plugin SMP_13_003.cc has these content :
---------------------------------------------------    void init() {
      // Full final state       const FinalState fs(-5.0, 5.0);       addProjection(fs, "FS");             // Z finders for muons       const ZFinder zfe(fs, -2.5, 2.5, 0*GeV, PID::ELECTRON, 15*GeV, 1500*GeV);       addProjection(zfe, "ZFE");
......    }

    void analyze(const Event& event) {
      const ParticleVector& z = zfe.bosons();      const double mass_z = z[0].mass();
......    }---------------------------------------------------

So I want to know the mass taken from the Z boson is pre-FSR or post-FSR?
Since I use the result of my rivet plugin (from YODA and then transform it to ROOT format),to compare with the pre-FSR and post-FSR mass of Z boson (generated by Powheg), and I find my rivet result is consistent to the pre-FSR instead of post-FSR.(previous one tell me that the FinalState object has already undergone the FSR, but since now I see inconsistent so I want to ask the part of ZFinder)
I put my rivet plugin (SMP_13_003.cc), and the comparison (snap shot ) in attachment. In comparison, the red point is the result of my rivet plugin, and the blue line is the pre-FSR or post-FSR.
Thanks.
Yu-hsiang
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