<div dir="ltr">The validation is running now. Will let you know the outcome when it finishes (~hours).<div> </div><div>Chris</div><div class="gmail_extra"> <div class="gmail_quote">On Tue, Sep 15, 2015 at 5:14 PM, Andy Buckley <<a href="mailto:andy.buckley@cern.ch" target="_blank">andy.buckley@cern.ch</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Done, and pushed. I added an optional "mass" arg to the MissingMomentum::visibleMom and ::missingMom methods, and fixed up WFinder to use the zero-mass target rather than subtracting the visible momentum from (sqrtS,0,0,0) -- cunning, but I think it meant that the vector still had the mass of what went down the beampipe, i.e. high! This definitely needs a validation run. Maybe we could even try running a few WFinder analyses in the system ~now, Chris, to make sure I didn't completely balls it up? Andy<div><div> On 15/09/15 15:17, David Grellscheid wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi all, I agree with zero mass as the default. Maybe we can introduce a target mass in the MissingMomentum projection, to give theory input in the analyses that may need it. But in the absence of any other information the m=0 assumption is certainly a good one. David On 15/09/2015 10:09, Chris Pollard wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> I'm in favor of only exposing the MissingMomentum 3-momentum. I also agree that setting the neutrino mass to zero when solving for the W mass is the right way to go, although David G should comment on whether this would break BSM reinterpretations. Chris On Tue, Sep 15, 2015 at 1:50 AM, Andy Buckley <<a href="mailto:andy.buckley@cern.ch" target="_blank">andy.buckley@cern.ch</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi all, A summer student working with Chris and I spotted last week that the W returned from WFinder is still nonsensical. The cuts are ok, and the lepton is also fine, but the use of the full 4D missing ET vector to make the "pseudo-neutrino" messes up because that vector has an energy component equal to the energy sum of all the in-acceptance particles used to calculated the *visible* momentum against which the missing one is balanced. One option would be to reduce the MissingMomentum to the transverse vector only, but that seems too far because it should also be usable in e+e- colliders. It also seems wrong to give the missing momentum vector a null mass, because while that's fine for neutrinos it's wrong for BSM invisibles. I suggest that we change the MissingMomentum interface (again... I already made some enhancements for 2.4.0) to only expose a 3-momentum. The E component is really a misleading accident. What do you think? Any objections or alternative suggestions? (A user-specified missing momentum mass target, maybe?) Similarly, we can't just restrict the WFinder to use transverse mass due to e+e- compatibility. But there we do have a definite hypothesis that the missing momentum vector should be a neutrino, so we could set the pseudo-nu mass to zero, and feed that into the pseudo-W mass in the case that full rather than transverse mass is used. Again, thoughts? Andy PS. Still waiting for analysis integration volunteers. I'll start forcibly assigning them if I don't hear soon (this is the procedure we agreed on!), so this is your chance to take a quick look at the tarballs and pick a couple of easy ones ;-) -- Dr Andy Buckley, Lecturer / Royal Society University Research Fellow Particle Physics Expt Group, University of Glasgow _______________________________________________ Rivet mailing list <a href="mailto:Rivet@projects.hepforge.org" target="_blank">Rivet@projects.hepforge.org</a> <a href="https://www.hepforge.org/lists/listinfo/rivet" rel="noreferrer" target="_blank">https://www.hepforge.org/lists/listinfo/rivet</a> </blockquote> _______________________________________________ Rivet mailing list <a href="mailto:Rivet@projects.hepforge.org" target="_blank">Rivet@projects.hepforge.org</a> <a href="https://www.hepforge.org/lists/listinfo/rivet" rel="noreferrer" target="_blank">https://www.hepforge.org/lists/listinfo/rivet</a> </blockquote> _______________________________________________ Rivet mailing list <a href="mailto:Rivet@projects.hepforge.org" target="_blank">Rivet@projects.hepforge.org</a> <a href="https://www.hepforge.org/lists/listinfo/rivet" rel="noreferrer" target="_blank">https://www.hepforge.org/lists/listinfo/rivet</a> </blockquote> -- Dr Andy Buckley, Lecturer / Royal Society University Research Fellow Particle Physics Expt Group, University of Glasgow _______________________________________________ Rivet mailing list <a href="mailto:Rivet@projects.hepforge.org" target="_blank">Rivet@projects.hepforge.org</a> <a href="https://www.hepforge.org/lists/listinfo/rivet" rel="noreferrer" target="_blank">https://www.hepforge.org/lists/listinfo/rivet</a> </div></div></blockquote></div> </div></div>