<html><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1433842364492_3216">Hi all,</div><div id="yui_3_16_0_1_1433842364492_3216"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">I have question for the FinalState and the ZFinder in Rivet. </div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">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? )</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"> </div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">For example, my Rivet plugin <span style="font-family: 'Helvetica Neue', 'Segoe UI', Helvetica, Arial, 'Lucida Grande', sans-serif; line-height: 20px; white-space: nowrap;" class="" id="yui_3_16_0_1_1433842364492_4110"><font size="3" id="yui_3_16_0_1_1433842364492_4184">SMP_13_003.cc has these content :</font></span></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">---------------------------------------------------</div><div class="" style="" id="yui_3_16_0_1_1433842364492_3870"> void init() {</div><div class="" style="" id="yui_3_16_0_1_1433842364492_3869"><br class="" style=""></div><div class="" style="" id="yui_3_16_0_1_1433842364492_3868"> // Full final state</div><div class="" style="" id="yui_3_16_0_1_1433842364492_4198"> const FinalState fs(-5.0, 5.0);</div><div class="" style="" id="yui_3_16_0_1_1433842364492_4199"> addProjection(fs, "FS");</div><div class="" style="" id="yui_3_16_0_1_1433842364492_4061"> </div><div class="" style="" id="yui_3_16_0_1_1433842364492_4084"> // Z finders for muons</div><div class="" style="" id="yui_3_16_0_1_1433842364492_4201"> const ZFinder zfe(fs, -2.5, 2.5, 0*GeV, PID::ELECTRON, 15*GeV, 1500*GeV);</div><div class="" style="" id="yui_3_16_0_1_1433842364492_4103"> addProjection(zfe, "ZFE");</div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838"><br></div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838">......</div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838"> }</div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838"><br></div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838"><br></div><div class="" style="" id="yui_3_16_0_1_1433842364492_3838"> </div><div class="" dir="ltr" style="" id="yui_3_16_0_1_1433842364492_4234"> void analyze(const Event& event) {</div><div class="" dir="ltr" style="" id="yui_3_16_0_1_1433842364492_4233"><br></div><div id="yui_3_16_0_1_1433842364492_3216"> </div><div class="" dir="ltr" style="" id="yui_3_16_0_1_1433842364492_3859"> const ParticleVector& z = zfe.bosons();</div><div id="yui_3_16_0_1_1433842364492_3216"> </div><div class="" dir="ltr" style="" id="yui_3_16_0_1_1433842364492_3867"> const double mass_z = z[0].mass();</div><div id="yui_3_16_0_1_1433842364492_3216"><br></div><div class="" id="yui_3_16_0_1_1433842364492_3838" style="">......</div><div class="" id="yui_3_16_0_1_1433842364492_3838" dir="ltr" style=""> }</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">---------------------------------------------------<br></div><div id="yui_3_16_0_1_1433842364492_3216"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">So I want to know the mass taken from the Z boson is pre-FSR or post-FSR?</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">Since I use the result of my rivet plugin (from YODA and then transform it to ROOT format),</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">to compare with the pre-FSR and post-FSR mass of Z boson (generated by Powheg), </div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">and I find my rivet result is consistent to the pre-FSR instead of post-FSR.</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">(previous one tell me that the FinalState object has already undergone the FSR, </div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">but since now I see inconsistent so I want to ask the part of ZFinder)</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">I put my rivet plugin (<span style="font-family: 'Helvetica Neue', 'Segoe UI', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: medium; line-height: 20px; white-space: nowrap;" class="" id="yui_3_16_0_1_1433842364492_4417">SMP_13_003.cc), and the comparison (snap shot ) in attachment. </span></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">In <span style="font-family: 'Helvetica Neue', 'Segoe UI', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: medium; line-height: 20px; white-space: nowrap;" class="" id="yui_3_16_0_1_1433842364492_4498">comparison, the red point is the result of my </span>rivet plugin, and the blue line is the pre-FSR or post-FSR.</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">Thanks.</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr">Yu-hsiang</div><div id="yui_3_16_0_1_1433842364492_3216" dir="ltr"><br></div></div></body></html>