[ee] TCS proposal ready for collaboration review

Wed Apr 25 21:36:22 EDT 2012

Hello Everyone,

Please find below a draft for the response to our CLAS reviewers.

Best Regards,

     Pawel

----------------------------------

Dear Igor and Mher,

Thank you again for your very helpful comments. We have tried to revise 
the proposal draft accordingly. Please find a new version at.
https://userweb.jlab.org/~turonski/tcs/proposal_clas/tcs_clas12-proposal.pdf

In particular, we have made a clearer statement about the J/Psi 
measurement and mentioned the role of the forward tagger in a future 
proposal on J/Psi electroproduction. We have further tried make the 
explanation of the relation between R and R' more clear, and to make the 
theory part somewhat more accessible.

Most of the other questions have been addressed, directly or indirectly, 
through a rewrite of the relevant parts of several section, and we feel 
that this would be a good time to provide you with the new version for 
further comments in view of the relatively short time that remains. The 
three things we have not addressed yet are the figures, references, and 
the discussion on systematic uncertainties. The latter is something we 
are currently working on. Also, please note that in the current layout 
of the proposal, projections for errors are all given in the projected 
results section.

Since most of the itemized questions were, as mentioned above, addressed 
directly in the text, we provide specific answers below only to those 
questions/comments that we thought might require some further 
clarifications. The original page, section, and line references are 
given for simplicity.

Abstract: the range between the rho' and J/Psi is aimed at avoiding the 
meson resonance region in the invariant mass of the lepton pair. This is 
discussed in more detail at the beginning of Section 2B, but the full 
explanation was a little long for the abstract. Hopefully the update to 
the main text addresses this issue.

pg. 6 [Sect 2B, line 3]: The hard scale, provided by the photon 
virtuality, makes it possible to factorize the hard scattering on a 
single quark and the residual soft interactions, represented by the GPD, 
which carry the information on nucleon structure.

pg. 15 [Sec. E, para 2, line 1]: Quasi-model independent refers here to 
that the fits are constrained only by the data without imposing any 
constraints from theoretical models. This makes things more complicated 
in the sense that there are more degrees of freedom, but also does not 
bias the result.

pg 16 [Sec. H, line 10]: Rafayel's thesis shows the results from the 
analysis outlined in the LOI.

pg 23 [Sec. B] In the acceptance simulations we used FastMC. For the 
actual data analysis we will use GEMC. However, this is an important 
point, and one of the main reasons we also propose to take data with 
both torus polarities. This will hopefully allow us to understand 
effects related to track charge.

Best Regards,

     Pawel

On 4/17/2012 12:45 PM, Igor Strakovsky wrote:
> Dear Pawel and friends,
>
> Overall, this is a very promising proposal addressed to a very
> interesting physics.  Unfortunately, it has too much theory and less 
> experimental details.  Let us suggest to reduce theory part and drop
> off so many theoretical details which are really unnecessary for the 
> experimental proposal.  In the experimental part, just due to the
> acceptance effect and invariant mass range, phase space of integration
> is destroyed, so guess another strong point authors should demonstrate
> is that how close are generated weighted cross section, R or R' with 
> reconstructed one.
>
> As far as well known, the Forward Tiger which the Italian group is
> building is a new hardware for CLAS12.  Are you going to use it?  Did
> you consider any benefits from FT to your proposal?
>
> There are several technical issues...
> The quality of most of figures require some polishing. There are a lot
> of missed labels and characters are too small to read them. List of
> Refs has many hidden sources as [44,45,52,53,54,55,56].  You have to
> give links on the open sources.  Then please use the standard Phys
> Rev stile for references.
>
> Nevertheless, we would like to make some remarks and raise some
> questions that should be considered.  Let us put them in order.
>
> Igor
> Mher
> --------------------------------------------------------------
> - Abstract: You have to say - why energy range between rho' and J/Psi
>  is attractive.
>
> - pg 3 [Intro, para 1, line 15]: You cannot 'explain' and then 'explore'.
>   Please fix it.
>
> - pg 3 [Intro, para 2, line 5]: It is unclear, please re-phrase 'in terms
>   of universal (process-independent)'.
>
> - pg 4 [2nd bullet, line 2]: It is unclear, please re-phrase 'a broad
>   range of light-cone fractions'.
>
> - pg 4 [3rd bullet, line 1]: What other data?
>
> - pg 4 [3rd bullet, line 2]: What 'global QCD  analysis' means.
>
> - pg 4 [3rd bullet, line 4]: Amplitudes of what?
>
> - pg 4 [2nd para below 3rd bullet]: Please make your position clear -
>   what purpose to do J/Psi photoproduction measurements.  If to study
>   systematics, then you have to say how you are going to do that.  If
>   there is a special interest to such kind of measurements, then spell
>   out the physics.
>
> - pg 6 [Sec. B, para 1, line 3]: What 'hard scale' means?
>
> - pg 8 [Fig 4]: There is no label for x-axis.
>
> - pg 8 [para 1, line 3]: 'new' ==> 'additional'.  Why that is important
>   here?
>
> - pg 14 [Fig 8]: There are no labels for both x- and y-axes.
>
> - The authors presented their ability to do data analyses (like they did
>   with 6 GeV data) and they show that they can extract amplitudes using
>   CFF fitting procedure of Ref. [36] (in which error propagation is not
>   clear for to us, so we guess case will be more strong with the plots
>   like Fig. 9 rather than fits).
>
> - pg 15 [Sec. E, para 2, line 1]: Please clarify 'quasi 
> model-independent'.
>   This experiment is model-dependent by default.  So, you can do nothing
>   model-independently.
>
> - pg 16 [Sec. G]: We do not think this Sec is necessary - too small
>   theoretical details.
>
> - pg 16 [Sec. H, line 5] It looks that Ref [47] is PhD thesis but you
>   mentioned LoI.  Please adjust text accordingly.
>
> - pg 16 [Sec. H, line 10]: g12 energy is 5.7 GeV - it is good to say it.
>
> - pg 17: On Fig 9 of the proposal guess the authors should add also
>   expected projections. Guess this is the 2 plots that can proof how
>   good CLAS12 can be and how strong is the proposal.
>
> - pg 17 [Fig 9]: R is somewhere in the text and Fig 4 & 9 captions. Then
>   R' is somewhere in the text.  What is the difference between R and R'.
>   Any formulas for that?
>
> - pg 18 [Sec I]: How you are going to determine (measure) J/Psi cross
>   sections? How is about acceptance and MC?  What stat and syst
>   uncertainties you are expecting?
>
> - pg 18 [Sec I, line 9]: 'and impact its impact' ?
>
> - pg 19: To make the case more strong guess one should present Fig. 11(b)
>   of Fig. [8] with the projections. Or put projections on Fig. 8 after
>   acceptance.
>
> - pg 19 [Fig 11 caption]: 'J/Psi production as'
>
> - pg 20 [line 1]: How many 'several' ?
>
> - pg 23 [Sec B]: It is well known that CLAS12 (as CLAS6 does) will have
>   different sensitivity to positive (better) and negative (worse) charged
>   particles. How you take into account this fact?
>
> - pg 28 [Ref [56]: How one can possible to consider a hidden predictions?
>   What uncertainties Vadim promises?
>
> - Fig. 25 is missing (at least in the version that we have).
>
> - pg 30: On Fig. 21, you clearly present holes in theta vs. phi plots.
>
> - pg 35 [Fig 27]: You have to give table with expected cross sections
>   and stat and syst uncertainties.  It is good to compare your
>   expectation with available experimental data.