[Rivet] Born and dressed level in Rivet

[David Grellscheid]

Hi Ulla,

> We didn't identify the FSR photons experimentally but we unfolded to a
> reference where a  lepton was dressed with the respective technical
> FSR implementation.

I'm sorry, I don't understand fully what you did there. The "reference" 
you refer to is a certain MC run with a certain setup? In that case 
isn't your unfolding dependent on that MC author's choice of where to 
put photon emissions in that specific version of the code?

> We checked that we get a similar correction in the
> standard generators, (pythia, herwig, sherpa..).

That doesn't mean it makes physical sense to split FSR from ISR photons.

   David