[Hybrid baryons] Proposal Draft - reorganized

Sun Apr 17 12:58:43 EDT 2016

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  *
> *                                                                                                                  *
> ***********************************************************************************
>
>
> _______________________________________________
> Hybrid_baryons mailing list
> Hybrid_baryons at jlab.org
> https://mailman.jlab.org/mailman/listinfo/hybrid_baryons

-- 
================================================
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