[Hybrid baryons] Table with cross section vs W, cos #theta, #phi.

[golovach at jlab.org]

Dear All,

Yes, I am using dsigma/dOmega_K in the CMS.
( sigma_T + eps*sigma_L
          + eps*sigma_TT*cos(2phi) + sqrt(eps*(1+eps))*sigma_LT*cos(phi) )
Ebeam = 6.6 GeV.

I agree, it is more reasonable to use dsigma/dOmega in any analysis.
We can switch to use the units mcbn/Ster, as they are always
used in papers.

Evgeny


> Dear All,
>
>   I guess in the blind analysis proposed by Volker we are working with
> just cross sections, assuming that all efficiencies*acceptance were
> already taken into account correctly for the extracted cross sections.
>
>  If our studies do not use the products efficiencies*acceptance, I can not
> see the reason to use electron scattering exclusive channel cross
> section.
>
>  I would propose Lucilla infer virtual photon cross section
> d^2sigma/dOmega_{K}. In physics analyses of the CLAS data in N* sector we
> always working with these cross sections, up to my knowledge.
>
>  I guess (Evgeny please check and correct as needed) Evgeny provided
> differential d^2sigma/dOmega_{K} virtual photon cross sections in the
> units GeV^-2/Ster. Note, the units are NOT mcbn/Ster.
>
>    Best Regards,
>                      Victor
>
> ----- Original Message -----
> From: "annalisa dangelo" <annalisa.dangelo at roma2.infn.it>
> To: "hybrid baryons" <hybrid_baryons at jlab.org>
> Sent: Saturday, May 7, 2016 6:01:33 AM
> Subject: Re: [Hybrid baryons] Table with cross section vs W, cos
> #theta,	#phi.
>
> Dear Victor, Evgeny and All,
>
> Lucilla has computed the four-fold electron scattering differential
> cross section:
> d^4 sigma/dQ2 dW dOmega_k, as Victor defines in point a).
>
> Since dW units are GeV and Q2 units are GeV{2} the four-fold electron
> scattering differential cross section units
> are micro barn GeV{-3}/sr.
>
> Since the virtual photon Flux and polarization depend on the electron
> beam energy, we should also specify that the
> tables were evaluated at 6.6 GeV. (Lucilla please correct me if I am
> wrong)
>
> All the best
> Annalisa
> Il 06/05/16 20:25, Viktor Mokeev ha scritto:
>> Dear Colleagues,
>>
>>   We need to clarify which cross section you are using. Whether they are
>> a)dsigma/(dW*dQ^2domega_{K}} exclusive cross sections for electron
>> scattering, or
>> b)dsigma/domega_{K} for exclusive virtual photon cross section.
>>
>> My guess is: Evgeny is using b) with units GeV{-2}/Ster
>>
>> Lucilla uses
>>
>> mcbarn/(Sr GeV^3)
>>
>> It looks like the electron scattering exclusive KY cross section in
>> which virtual photon cross sections was converted from GeV{-2}/Ster to
>> mcbarn/(Sr), while GeV^{-3} comes from 1/(dW*dQ^2) from extra
>> differentials for exclusive electron scattering cross section.
>>
>> Evgeny and Lucilla, please come to common units and common cross
>> sections. Both a) and b) cross sections are equally fine. GeV{-2}/Ster
>> or
>> mcbarn/Ster units are equally fine. However, you have to use the common
>> units in order to be able to fit the cross sections from each other.
>>
>>    Best Regards,
>>                      Victor
>>
>> ----- Original Message -----
>> From: "Evgeny Golovach" <golovach at jlab.org>
>> To: "hybrid baryons" <hybrid_baryons at jlab.org>
>> Sent: Friday, May 6, 2016 2:05:25 PM
>> Subject: [Hybrid baryons] Table with cross section vs W, cos #theta,
>> #phi.
>>
>> Dear All,
>>
>> Lucilla, I am sending you my table.
>> It is in the same format.
>> I guess, your cross sections is in the units of GeV^{-2}.
>> I used the same units.
>>
>> Regards,
>>    Evgeny
>>
>>
>>> Dear all,
>>>
>>> here is the table with the unpolarized cross section vs phi, cos theta
>>> and W.
>>> We used ifstream and ofstream classes to read and write it.
>>>
>>> Best regards,
>>>
>>> Annalisa and Lucilla_______________________________________________
>>> Hybrid_baryons mailing list
>>> Hybrid_baryons at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/hybrid_baryons
>>>
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>
> --
> ================================================
> Prof. Annalisa D'Angelo
> Dip. Fisica, Universita' di Roma "Tor Vergata"
> INFN Sezione di Roma Tor Vergata, Rome Italy
> email:annalisa.dangelo at roma2.infn.it
> Jefferson Laboratory, Newport News, VA USA
> Email: annalisa at jlab.org
> Tel: + 39 06 72594562
> Fax: + 39 06 2040309
>
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