[Rivet] CMS_2013_I1122847 (Forward-backward asymmetry in DY)

[Andy Buckley]

Thanks both for finding the source of the discrepancy. This seems just
fine to me, but it's definitely good to (re)check that everything is as
expected!

Cheers,
Andy


On 26/02/15 09:37, Albert Knutsson wrote:
> 
> Hi Holger,
> 
> yes that is correct.
> 
> We usually aim for exactly the same MC prediction for the validation.
> This time, as far as I understand (Markus in cc, please correct me if
> I'm wrong), the original MC sample used in the paper had been deleted,
> and for practical reasons a new one was produced with pythia8.
> 
> Cheers,
> Albert
> 
> 
> On 26/02/15 10:30, Holger Schulz wrote:
>> On 26/02/15 07:47, Albert Knutsson wrote:
>>> Dear Holger,
>>>
>>> The predictions in the paper are POWHEG+PYTHIA6. The predictions in
>>> the validation plots are POWHEG+PYTHIA8 (as the file name of the
>>> validation plots I sent indicate). Both of the predictions are
>>> describing the data within the uncertainties of the data.
>> Hi Albert,
>>
>> thanks for the clarification. Just to clarify, do I assume correctly
>> that the plots you made were made using a standalone
>> run of powheg with pyhtia8 then?
>>
>> Ideally, the validation process should use the exact same hadron level
>> datasets used
>> in the analysis simply because then the results in the paper and the
>> rivet plugin
>> must be identical --- which helps to spot mistakes in the
>> implementation on one hand
>> but also to reveal possible shortcomings in rivet.
>>
>> Best,
>> Holger
>>
>>
>>
>>
>>>
>>> It is already written in the info-file that QED radiation for the
>>> leptons should be turned off. I added the the word born level now.
>>> New tar-ball attached.
>>>
>>> Thanks and cheers,
>>> Albert
>>>
>>>
>>> On 25/02/15 16:36, Holger Schulz wrote:
>>>> Thanks Albert.
>>>>
>>>> So I am comparing Figure two, top left plot in the paper, blue line,
>>>> i.e. "POWHEG (CT10) + PYTHIA (Z2) with PDF uncertainties"
>>>>
>>>> with d03-x01-y01, red line from your plots ("powheg2").
>>>>
>>>> They look kind of similar but are not identical. E.g. the last three
>>>> bins in the paper show the MC prediction to be consistently above
>>>> the data while your plots do not reflect that.
>>>>
>>>> Could you please tell me how exactly you validate your plugins?
>>>> I.e. are you running the plugin over the exact same dataset that
>>>> is equivalent to the blue line in the paper?
>>>>
>>>> Also, could you mention in the .info file that this analysis is Born
>>>> level
>>>> only, please?
>>>>
>>>> Thanks,
>>>> Holger
>>>>
>>>>
>>>>
>>>> On 25/02/15 13:38, Albert Knutsson wrote:
>>>>>
>>>>> Dear Holger,
>>>>>
>>>>> please find them attached.
>>>>>
>>>>> Cheers,
>>>>> Albert
>>>>>
>>>>> On 25/02/15 12:52, Holger Schulz wrote:
>>>>>> On 25/02/15 07:40, Albert Knutsson wrote:
>>>>>>> Dear Rivet developers,
>>>>>>>
>>>>>>> please find attached the validated CMS plugin for
>>>>>>> "Forward-backward asymmetry in Drell-Yan lepton pairs at 7 TeV", 
>>>>>>> CMS_2013_I1122847.
>>>>>>>
>>>>>>> Thanks in advance for putting it on the public download area and
>>>>>>> including it in a future release.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Albert on behalf of CMS
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Rivet mailing list
>>>>>>> Rivet at projects.hepforge.org
>>>>>>> https://www.hepforge.org/lists/listinfo/rivet
>>>>>> Hi Albert,
>>>>>>
>>>>>> would you mind sending a link to your plots that show that the
>>>>>> plugin is validated?
>>>>>>
>>>>>> Best,
>>>>>> Holger
>>>>>
>>>>
>>>
>>
> 
> 
> 
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-- 
Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow