[Hybrid baryons] Proposal Draft - reorganized
Daniel Carman
carman at jlab.org
Mon Apr 18 08:46:42 EDT 2016
Annalisa,
Victor did some further work on the early sections of the proposal this weekend after I sent around
my comments. He sent his updates to me for comment and I think they are reasonable. Based on
what is now available for the introductory parts of the proposal, I would propose that we freeze the
first part of the proposal (Section 1 through Section 3.2) so that I can begin to polish it. That way I
don’t have to deal with editing all 70 pages over just a couple of days this weekend. Let me know
if you agree and I will begin my work.
Regards,
Daniel
> On Apr 17, 2016, at 12:58 PM, Annalisa D'Angelo <annalisa.dangelo at roma2.infn.it> wrote:
>
> Dear Daniel,
> Thank you!!
> Annalisa
>
> Il 17/04/16 18:52, Daniel Carman ha scritto:
>> Annalisa et al.,
>>
>> I have just finished reading the available draft of the hybrid baryon proposal that was circulated yesterday. I have extensively
>> marked up my copy, but I wanted today to share only my “highest" level of comments as we work to shape a "presentable”
>> version of this proposal to meet the CLAS Collaboration review deadline of next Monday.
>>
>> 1) The proposal as it stands, while still rough and hastily written in some areas, is not all that bad. In fact, I am certain that we
>> can converge this week on a draft that will represent us well for the collaboration review.
>>
>> 2) One area of weakness that needs to be addressed is that there are no references to the extensive existing measurements
>> published by CLAS for KY electroproduction. These measurements needs to be described in some level of detail and proper
>> references included. I can provide this part along with references.
>>
>> 3) The two existing elements of the CLAS12 N* program (E12-09-003 and E12-06-108A) should be described somewhere in
>> the introduction in a concise fashion with appropriate references.
>>
>> 4) The proposal draft will need extensive clean-up with respect to grammar, syntax, and style. As I will be responsible for this,
>> I would like to get the “frozen” proposal draft (and all files) no later than Friday afternoon (Apr. 22) so that I can complete this
>> work over the weekend. I will finish my work by Apr. 24 and send the draft to the hybrid group for a final chance to look at it
>> before submission on Apr. 25.
>>
>> 5) Section 3. I found the "Old Version" much better written and more complete than the paragraphs that follow in the “New
>> Version". I propose to keep the text highlighted in blue and to delete the text on pp. 12 and 13 starting from "As discussed in
>> section 2.2, according ...” until "... channels such as $\phi(1020N$, $K^+\Lambda$.".
>>
>> 6) The first bullet of Section 3.1 makes no sense to me.
>>
>> 7) Explain the curves on Fig. 7 and Fig. 8.
>>
>> 8) Section 3.3. At the top of pp. 20 is a bit about "In collaboration with the JPAC ..." that does not seem to fit. Lots of words but the
>> relevance to the discussion does not seem to fit.
>>
>> 9) Section 5. The intro paragraph is all about KY and should be moved to Section 6.
>>
>> 10) The acceptance of CLAS12 for eppi+pi- and eK+ppi- can be misleading if a proper cut on the momentum for low momentum
>> tracks in the Central Detector is not considered. The minimum momentum tracks accepted by the CTOF is ~300 MeV. Is there a
>> pmin cut in effect?
>>
>> 11) Section 5.4. The second paragraph here makes no sense to me.
>>
>> 12) What is the purpose of Fig. 21? It should be better integrated into the text and redone with I=-3375A torus current.
>>
>> 13) Replace Fig. 25 and Fig. 26 with I=+/-3375 A for the torus.
>>
>> 14) Section 6.3. This business about "Lambda Separation %” and "Sigma0 Separation %" should be eliminated. For cross section
>> observables the hyperons can be separated with a proper line-shape analysis such as has been done in our existing CLAS
>> publications. So, remove the vertical lines on Figs. 27 and 28 and eliminate this discussion.
>>
>> 15) Section 6.4. Rate estimates should be shown only for final torus current choice of -3375 A. All of the other conditions listed only
>> serve to distract.
>>
>> 16) Section 6. Somewhere in the section a crisp argument has to be made about value added at running at both 6.6 GeV and 8.8 GeV.
>> What are the different kinematic ranges accessible at each beam energy and why are these different ranges essential for a successful
>> experiment?
>>
>> 17) Section 7. Nowhere are the different observables that will be measured succinctly laid out, especially for K+Y. The plan is to measure
>> the differential cross sections and to separate the structure functions sigU, sigLT, sigTT, and possible sigLT', as well as to measure the
>> induced and transferred hyperon polarization. This needs to be clearly discussed and why these observables are important. Also it needs
>> to be mentioned that the interference structure functions and polarization observables might be even more sensitive to hybrid baryons
>> that measurements of differential cross sections alone. Certainly they can only add additional sensitivity in the search for new baryon
>> states (hybrid or conventional). These observables and their potential sensitivities are not really mentioned or discussed at all in the
>> proposal.
>>
>> 18) Section 7.6. The discussion here is a bit muddy and misleading. Table 5 shows the minimal value of the A1/2 electrocouplings vs. Q2,
>> but under the condition that only the scattered electron is used to define the trigger. A tepid statement is made that with a two- or
>> three-prong trigger this minimal value improves. I think that some additional table must be included on what this improvement is with
>> our expected trigger condition for the experiment.
>>
>> 19) Section 7.7. Replace Tables 7 and 8 with values for I=-3375 A torus current.
>>
>> 20) Replace Figs. 34, 35, 36, 37 with I=-3375 A torus current.
>>
>> 21) Section 7.8 needs some attention to introduce this approach to define our sensitivity to finding hybrids. This includes mentioned the
>> use of this chi-squared approach from Bonn-Gatchina. The section should also be expanded following Volker' recent suggestion of
>> scanning the chi-squared space assuming different quantum numbers for the resonance than were used to generate it.
>>
>> 22) Section 8. The justification of the 30 days at each beam energy needs to be made more complete. We need to carefully define our
>> statistical requirements based on a certain minimum threshold value for the hybrid electrocoupling. The running time needs to be justified
>> showing how the minimum electrocoupling value increases as a function of reduced beam time.
>>
>> 23) Page 59. Figs. 39 and 40 are not referenced in the text.
>>
>> 24) Section 9. The summary should include explicit mention to the two existing elements of the CLAS12 N* program, E12-09-003 and
>> E12-06-108A, at 11 GeV.
>>
>> 25) Are Appendices A and B needed for this proposal? This is fairly elementary stuff. If deemed to be helpful to the proposal, the formalism
>> section on KY should follow what I have developed as the RPR formalism is based on what I have defined in our published KY papers from
>> CLAS.
>>
>> Let me know if folks have any questions or comments on this.
>>
>> Regards,
>> Daniel
>>
>> ***********************************************************************************
>> * *
>> * Dr. Daniel S. Carman e-mail : carman at jlab.org *
>> * Staff Scientist office : (757)-269-5586 *
>> * Jefferson Laboratory web: http://userweb.jlab.org/~carman *
>> * *
>> ***********************************************************************************
>>
>>
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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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***********************************************************************************
* *
* Dr. Daniel S. Carman e-mail : carman at jlab.org *
* Staff Scientist office : (757)-269-5586 *
* Jefferson Laboratory web: http://userweb.jlab.org/~carman *
* *
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