[Rivet] Question concering PromptFinalState projection

[Dominic Hirschbuehl]

Hi Andy, Chris,

I completely agree, that we should not use the fortran generators
anymore, however they are still default generators for a lot of 8 TeV
analyses ....

So maybe one should put somewhere a disclaimer, that at least our top
routines cannot be used with fortran herwig.

Cheers
  Dominic

On Thu, Jan 26, 2017 at 10:59:52AM +0000, Andy Buckley wrote:
> Exactly. I think we may be now more than 10 years past the point
> that it was declared superseded and unsupported ;-)
> 
> Andy
> 
> 
> On 25/01/17 19:10, Christian Gutschow wrote:
> >Hi,
> >
> >the Rivet routines work perfectly fine with the Herwig shower (!) — it’s
> >just Fortran Herwig that doesn’t comply with the HepMC standard, for
> >which the routines might not work. All the more reason to move to the
> >modern incarnations of Herwig...
> >
> >Cheers,
> >Chris
> >
> >>On 25 Jan 2017, at 17:31, Dominic Hirschbuehl <dhirsch at mail.cern.ch
> >><mailto:dhirsch at mail.cern.ch>> wrote:
> >>
> >>Hi Andy,
> >>
> >>thanks a lot for the quick answer.
> >>It is indeed Fortran Herwig and I ran over a MC12 sample. Maybe the
> >>rewriter was not used for this sample.
> >>
> >>However, does this mean, that we need to put some disclaimer to our
> >>Rivet routines, that they don't work for the Herwig shower, since
> >>everybody outside ATLAS won't have the rewriter, right?
> >>
> >>Cheers
> >> Dominic
> >>
> >>On Wed, Jan 25, 2017 at 05:24:21PM +0000, Andy Buckley wrote:
> >>>Hi Dominic,
> >>>
> >>>Is this *Fortran* Herwig?
> >>>
> >>>Indeed it uses non-standard status codes, so Rivet's algorithms will
> >>>break. But in ATLAS we added a Herwig status rewriter, to make it
> >>>compliant -- is that not being used in your sample?
> >>>
> >>>The restriction to look at status 2 only (because status 1 can't be
> >>>an ancestor) is maybe a bit extreme: we could also allow status
> >>>codes > 10 to be used (the MC range if I remember correctly). But
> >>>then we wouldn't know what sort of generator-dependence we'd be
> >>>introducing: for example Herwig++ uses status 11 for everything that
> >>>isn't 1, 2, or 4 so we could end up walking up precisely the sort of
> >>>unphysical debug trees that the code is trying to avoid...
> >>>
> >>>Short answer: the generator needs to be compliant with the HepMC
> >>>status scheme. But I thought we had already modified FHerwig in that
> >>>way.
> >>>
> >>>Andy
> >>>
> >>>
> >>>On 25/01/17 16:55, Dominic Hirschbuehl wrote:
> >>>>Dear all,
> >>>>
> >>>>I have a question concerning the PromptFinalState projection.
> >>>>I did a study on acceptences of lep+jets ttbar events, where I found an
> >>>>unexpected differences between Powheg+Pythia6 and Powheg+Herwig samples.
> >>>>The differences occured already on the level of the lepton acceptance,
> >>>>which includes a dilepton veto.
> >>>>
> >>>>After some investigation I have the suspicion, that leptons from hadron
> >>>>decays are counted as prompt leptons.
> >>>>
> >>>>Looking to the actual implementation of isPrompt I found this line
> >>>>of code:
> >>>>if (ancestor->status() != 2) continue; // no non-standard statuses or
> >>>>beams to be used in decision making
> >>>>
> >>>>Is there a reason to restrict the status codes to 2?
> >>>>If I print out all ancestors of a "prompt lepton" from a Herwig
> >>>>showered event
> >>>>I get:
> >>>>
> >>>>  pdg = 2212 status = 101 0 1
> >>>>  pdg = 2212 status = 102 0 1
> >>>>  pdg = 21 status = 121 1 0
> >>>>  pdg = 21 status = 122 1 0
> >>>>  pdg = 6 status = 123 1 0
> >>>>  pdg = 6 status = 143 1 0
> >>>>  pdg = 6 status = 3 1 0
> >>>>  pdg = 6 status = 155 1 0
> >>>>  pdg = 24 status = 123 0 0
> >>>>  pdg = 24 status = 3 0 0
> >>>>  pdg = 24 status = 155 0 0
> >>>>  pdg = 4 status = 124 1 0
> >>>>  pdg = 4 status = 144 1 0
> >>>>  pdg = 4 status = 2 1 0
> >>>>  pdg = 21 status = 2 1 0
> >>>>  pdg = 4 status = 158 1 0
> >>>>  pdg = -2 status = 158 1 0
> >>>>  pdg = 91 status = 183 0 0
> >>>>  pdg = 411 status = 197 0 1
> >>>>
> >>>>which would indicate that the identified lepton actually comes fomr a
> >>>>hadron.
> >>>>
> >>>>Do I miss something?
> >>>>
> >>>>Thanks in advance
> >>>>Dominic
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>_______________________________________________
> >>>>Rivet mailing list
> >>>>Rivet at projects.hepforge.org <mailto:Rivet at projects.hepforge.org>
> >>>>https://www.hepforge.org/lists/listinfo/rivet
> >>>>
> >>>
> >>>
> >>>--
> >>>Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
> >>>Particle Physics Expt Group, University of Glasgow
> >>
> >>--
> >>/---------------------------------------------------------------------\
> >>|                     Dr. Dominic Hirschbuehl                           |
> >>\   Bergische Universitaet Wuppertal - Exp. Elementarteilchenphysik   /
> >>/  hirsch at physik.uni-wuppertal.de
> >><mailto:hirsch at physik.uni-wuppertal.de> / dominic.hirschbuehl at cern.ch
> >><mailto:dominic.hirschbuehl at cern.ch>       \
> >>|       office : D.09.22    phone  : 0049 - 202 - 439 - 3751
> >>          |
> >>\---------------------------------------------------------------------/
> >>_______________________________________________
> >>Rivet mailing list
> >>Rivet at projects.hepforge.org <mailto:Rivet at projects.hepforge.org>
> >>https://www.hepforge.org/lists/listinfo/rivet
> >
> >
> >
> >
> > —
> >
> > Dr. Christian Gütschow
> >
> > Department of Physics and Astronomy
> > University College London
> > Gower Street
> > London WC1E 6BT
> >
> > > D10 Physics Building
> > > +44 (0)20 7679 3775
> > > chris.g at cern.ch <mailto:chris.g at cern.ch>
> >
> >
> >
> >
> 
> 
> -- 
> Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
> Particle Physics Expt Group, University of Glasgow

-- 
 /---------------------------------------------------------------------\
|                     Dr. Dominic Hirschbuehl                           |
 \   Bergische Universitaet Wuppertal - Exp. Elementarteilchenphysik   /
 /  hirsch at physik.uni-wuppertal.de / dominic.hirschbuehl at cern.ch       \             
|       office : D.09.22    phone  : 0049 - 202 - 439 - 3751           |   
 \---------------------------------------------------------------------/
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