[Rivet] bug in polar angle?

[Hendrik Hoeth]

Hi,

Thus spake Jonathan Butterworth (jmb at hep.ucl.ac.uk):

> Since Andy is away we won't get the full story now, I guess. But I
> suggest you do the following:
>
> - submit a ticket with high priority and an appropriate cc list
> - fix the polar angle definition
> - leave the ticket open so we can check the consequences with Andy
>   when he gets back.

done. The ticket number is #192 and the fix of polarAngle() is in
revisoin r874. I also deleted the workaround in the pseudorapidity
definition.

A quick grep in the sources shows that polarAngle is used in
H1_2000_S4129130, H1_1994_S2919893, and in the DISKinematics projection.
And of course everywhere where ET or the DISKinematics projection are
used. So that's the places which need checking.

> But I would have thought that this would be garing in the analyses
> using jet algorithms since while newer papers tend to use pT and y,
> the old ones use ET and pseudorapidity..

Current analyses at the tevatron also use ET and pseudorapidity. I
actually found the problem in a 2008 CDF analysis (underlying event)
when I plotted the average sum(ET) -- wich was flat around zero.

   Hendrik

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