[Rivet] Gentle reminders...

[Lars Sonnenschein]

Hello Andy et al.

On Mon, 11 May 2009, Andy Buckley wrote:

> Frank Siegert wrote:
> > Frank Siegert, Friday 08 May 2009:
> >> FastJet's D0ILCone does not seem to respect the pTmin that I pass to
> >> the constructor, so using:
> >>
> >>   FastJets jets(fs, FastJets::D0ILCONE, 0.5, 20.0*GeV);
> >>   const JetAlg& jetpro = applyProjection<JetAlg>(event, "Jets");
> >>   const Jets jets = jetpro.jetsByPt();
> >>
> >> also produces jets 10 GeV < pT < 20 GeV, because D0ILCone seems to have
> >> a default Et_min_ratio of 0.5 somewhere in the fastjet source code,
> >> which the jet_min_Et gets multiplied with.
> >> Is this to be expected? If so, we should definitely be aware of it in
> >> all D0ILCone analyses (and maybe others?). Workaround for me at the
> >> moment, is to specify an explicit pTmin to jetpro.jetsByPt(ptMin).
> > 
> > With this workaround the z+jets analyses seem to work alright.
> 
> Good. Can you check this with Gavin, Matteo & Gregory? 
> (fastjet at projects.hepforge.org, and maybe copy the Rivet list in on the 
> mail) Would this also be responsible for the factors of 2 that Hendrik 
> has reported appearing in Lars' CDF_2005 jet shape analysis?


At least the CDF_2005 jet shape analysis does make use of a different jet 
algorithm, namely: FastJets::CDFMIDPOINT

What is about the CDF_2008_S7782535.hh b-jet shape analysis?
It uses the same jet algo + jet shape projection.

	Lars

 
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Lars Sonnenschein    
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