[Rivet] CMS - 4 qcd rivet analyses

[Frank Siegert]

Hi Albert, all,

While comparing Monte-Carlo predictions to ATLAS and CMS inclusive jet 
pT spectra, I found that there is a factor of 2 in the normalisation of 
the CMS spectra which I think I don't understand:

   _hist_sigma.scale(crossSection()/sumOfWeights()/0.5/2, this);

I suppose you are dividing by 0.5 to get the dy binwidth and then divide 
by 2 to account for "|y| vs. y". The latter is definitely correct, but 
the original division by the binwidth of 0.5 is already done 
automatically by the "BinnedHistogram" which you have used here, so 
shouldn't be included in that scale call.

Unless anybody has an explanation/objection, I'm going to remove the 
"/0.5" now.

Cheers,
Frank



On 14/10/11 10:05, Albert Knutsson wrote:
>
> Dear Frank,
>
> thank you very much for checking the analyses and doing the updates and
> the bugfix!
>
> Cheers,
> Albert
>
>
> On 10/13/11 11:45 PM, Frank Siegert wrote:
>> Dear Albert + analysis authors,
>>
>> Thank you for providing these analyses as Rivet modules.
>>
>> I have added them to Rivet's SVN in c3440
>> http://projects.hepforge.org/rivet/trac/changeset/3440
>> and made a few modifications in c3441
>> http://projects.hepforge.org/rivet/trac/changeset/3441
>> (might be easier to view if you send the svn diff through wdiff)
>>
>> The summary of the modifications and corresponding diffs can be found
>> in the last link. They are mainly code maintenance, but also one
>> bugfix for weighted events in CMS_2011_S9120041 and a few guards
>> against NaN's. I have validated that before and after my changes the
>> distributions look exactly identical when running some Sherpa events
>> through them (except for the few distributions affected by the
>> weighted events bug).
>>
>> Best,
>> Frank
>>
>>
>> On 13/10/11 17:06, Albert Knutsson wrote:
>>> Dear Rivet developers,
>>>
>>> please find attached a tar-ball with the following 4 QCD analyses
>>> from CMS.
>>>
>>> - CMS_2011_S8950903 (Dijet Azimuthal Decorrelations)
>>> - CMS_2011_S9086218 (Inclusive Jet Cross Section)
>>> - CMS_2011_S9088458 (Ratio of the 3-jet over 2-jet cross section)
>>> - CMS_2011_S9120041 (Traditional UE at 0.9 and 7 TeV)
>>>
>>> Please include them in the official Rivet release.
>>>
>>> Thanks and cheers,
>>> Albert on behalf of CMS
>>>
>>>
>>>
>>> _______________________________________________
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>