[Rivet] Validation meeting

[Hendrik Hoeth]

Hi James,

Thus spake James Monk (jmonk at hep.ucl.ac.uk):

> The Atlas setup won't use any of the RivetGun params files, since the
> generator is steered by Athena.

Sure, but anyhow you find the parameters in those files, that's why I
pointed you to them. Running a Drell-Yan analysis with generic QCD
events is no fun. Statistics really suck.

> I could certainly run several jobs for different ckin(3) and ckin(4)
> but then the problem becomes merging them properly.

No CKIN(4). You don't want an upper cut -- harder event can always
radiate to meet your selection criteria and you don't want to loose
those events.

> I think you need the dsigma/dPT of the leading jet in  order to know
> the contribution from each plot.  Might it be worth  adding that plot
> to the analysis in future for that reason?

In the future we know what's in the bins (yoda ...). For now you can
simply fill the bins below some pT with one run, and above that pT with
another run. Provided that you keep CKIN(3) far enough below that
merging cut, where "far enough" in some of the analyses means 30 GeV
below.

> If I remember correctly, the data is split up into a min bias sample
> and a PT>20GeV sample anyway.  So I could take the min bias plots from
> a low ckin(3) sample and the pt 20 plots from a ckin(3) around 15 or
> so.

15 GeV is too high. CKIN(3)=10, not more. As I said in my last mail: You
can fill the minbias plots without CKIN(3) cut, and for the plots > 18 GeV
you can start with CKIN(3)=10 and if you want have another run with
CKIN(3)=20 to fill the bins above 30 Gev.

   Hendrik

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