[Rivet] [Rivet-svn] r2262 - trunk/doc

[Lars Sonnenschein]

Hello Frank
please find at http://www-d0.fnal.gov/~sonne/D0RunIcone.tgz
a preliminary version of the Run I cone algorithm.
It has to be treated confidently since it needs to be validated.
It can not be considered as an official version of D0 and 
should only serve for debugging and validation purposes.

The most detailed written documentation I could find is the public
Fermilab note:
FERMILAB-Pub-97/242-E

There are some subtleties:

Before the note (1997) the treatment of measured quantities
has been different (phi and theta computed differently from Snowmass, see 
Appendix p.31)
That might have an impact on the D0 1996 analysis.

I have used the Snowmass Et scheme (as the C++ code is anyway supposed to
reflect the latest status/version of the D0 Run I cone).

Maybe we need here a switch for both schemes?

The other subtlety is the Rsep parameter for NLO comparisons, which is 
discussed in the note. To reflect the found value Rsep =1.3
I have set the jet separation parameter TWOrad = 0.91 
(= Rsep=1.3/Rcone=0.7) as default value in the code.
I have not been able to find any default value for the TWOrad parameter
in the D0 software.

Concerning your suggestion to implement the D0 Run I code into Rivet
maybe Andy can comment.

If you could implement my code into Sherpa and tell me if it does make 
more sense, than your BFKL code we could maybe iterate and converge
to a validated version of my code on a reasonable time scale to get 
it implemented into fastjet.

So far

	Lars
 
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Dr. rer. nat. habil. Lars Sonnenschein    
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Home Institution:
III. Physikalisches Institut A, 26A204
Physikzentrum RWTH Aachen
52056 Aachen
Germany
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