[Primex] the latest version of the prl paper

[Ashot Gasparian]

   Dear Barry,

Thank you for your very careful reading of the draft and important 
suggestions. I will go through the items and make changes in the body part 
of the text. For the abstract part, I will update it based on your 
suggestions and send the draft again for the further collaboration 
discussions.

Thanks again,
Ashot


.............................................................
Ashot Gasparian                    Phone:(336)285-2112 (NC A&T)
Professor of Physics
Physics Department                       (757)-269-7914 JLab
NC A&T State University              Fax:(757)-269-6273 JLab
Greensboro, NC 27411               email: gasparan at jlab.org
.............................................................


On Sat, 10 Jul 2010, Barry Ritchie wrote:

> My only suggestions are intended to make the paper read more smoothly
> and accurately. Where there have been multiple changes within the same
> sentence or two, I have provided the suggested changes and, in most
> cases, provided an example of how the final results might read.
>
> BTW: An occasional misusage in the paper is the use of the word "error"
> when "uncertainty" is meant. The two words, of course, do not mean the
> same thing. The use of "error" is colloquial and often encountered in
> our conversations, but the latter word is what should be used in a
> formal context such as this paper.
>
> ---Barry
>
> Professor  Barry G. Ritchie
> Department of Physics
> Arizona State University
> Tempe, AZ  85287-1504
>
> Telephone: (480) 965-4707
> Fax: (480) 965-7954
>
>
> ===================================
>
>
> ADDRESSES
>
> 1. Eugene Pasyuk should have a footnote "Present address: Thomas
> Jefferson National Accelerator Facility, Newport News, VA 23606, USA"
>
> 2. If zip codes are to be used in addresses, then we should use "Tempe,
> AZ 85287" for ASU.
>
> ABSTRACT
>
> Some minor re-writing of the abstract will focus on the important
> points:
>
> 3. In the first sentence, I suggest "Differential cross sections...have
> been measured..." The words "High precision..." are only indicative of
> the current state of the art, not the physics interest.
>
> 4. We should remove redundancy in the first sentence by removing "two
> nuclei" thusly: "... photoproduction at forward angles for 12C and
> 208Pb, have been performed..." [though again, I would say "cross
> sections...have been measured" rather than "measurements... have been
> performed"
>
> 5. I would append an abbreviated portion of the second sentence to the
> first and reorder to emphasize the novel features of the measurement:
> "...decay width with a high-resolution multichannel calorimeter and a
> tagged photon beam."
>
> All put together, the abstract now reads something like:
>
> "Differential cross sections for pi0 photoproduction on 12C and 208Pb at
> forward angles have been measured for incident photon energies of 4.9 -
> 5.5 GeV with a high-resolution multichannel calorimeter and a tagged
> photon beam. These measurements were used to extract the decay width
> $\Gamma(\pi^0 \rightarrow \gamma\gamma)$, which was extracted by fitting
> the measured cross sections with recently updated theoretical models for
> the process. The resulting value for the decay width is $\Gamma(\pi^0
> \rightarrow \gamma\gamma)$ = 7.82 eV $\pm$ 1.8\% (stat.) $\pm$ 2.1\%
> (syst.)."
>
> PAGE TWO:
>
> 6. First paragraph: The use of "error" when "uncertainty" is meant
> occurs several times in this paragraph. The latter is better usage (as
> noted above) and also less confusing, particularly for readers whose
> first language is not English.
>
> 7. First paragraph, third sentence: Use of "error" for "uncertainty" and
> some other word issues: "The most accurate previously published
> measurement for the \pi^0 decay width was performed at Cornell by
> Browman et al. [9] with a 5.3% quoted total uncertainty:..."
>
> 8. First paragraph, fourth sentence: There is a repeated phrase and use
> of "error" for "uncertainty". Should read: "This result agrees within
> experimental uncertainty with the theoretical prediction."
>
> 9. First paragraph, fifth sentence: "Two other measurements [10, 11]
> with relatively large experimental uncertainties..."
>
> 10. First paragraph, sixth sentence: Choose better word than "done":
> "...prior to the current PrimEx experiment, was made by Atherton..."
>
> 11. I think the sentence beginning "Clearly, a new Primakoff type of
> experiment..." is gratuitous, particularly considering the next
> sentence, and should be removed.
>
> 12. In the next sentence, substitute "current" for "recent". (The photon
> tagger at JLab, for instance, has been in operation for over a decade.")
> We should also have a paragraph break at this sentence, since we have
> moved from a discussion of previous measurements to aspects of the
> current measurements.
>
> 13. Second column, first paragraph, first sentence: "...was performed in
> Fall 2004..."
>
> 14. Next sentence: I would suggest "...radiation length targets of 12C
> and 208Pb [14]."
>
> 15. Later on in the same paragraph, we should not use the capitalization
> indicated, since the reader can easily make the association:
> "...multichannel hybrid electromagnetic calorimeter (HyCal)..." In the
> same sentence, remove the word "at", which is unnecessary:
> "...multichannel hybrid electromagnetic calorimeter (HyCal) located 7.5
> m downstream..."
>
> 16. In the next sentence, the word "calorimeter" has become redundant
> due to the definition of the term HyCal, so we should write "HyCal
> consists of..."
>
> 17. Further along in the same paragraph, we need hyphens: "Twelve
> 5-mm-thick scintillator counters, located in front of HyCal, provided
> rejection of..."
>
> 18. In the next sentence, there are some word issues. The word
> "distance" is used when "space" or something similar is meant, and
> "covered" is used when we mean "enclosed". So we need something like "To
> minimize the decay photon conversion in the air space between them, the
> volume from the PS magnet to HyCal was enclosed by a helium bag at
> atmospheric pressure."
>
> PAGE THREE
>
> 19. First paragraph, first sentence: Remove unneeded commas: "The event
> yield (number of \pi^0 events for each production angle bin) was
> obtained from the data by applying the selection criteria described
> above and fitting the experimental distributions for each angular bin."
>
> 20. First paragraph, last sentence: Use of "error" when "uncertainty" is
> meant: "...largest contributions to the total systematic uncertainty."
>
> 21. Second paragraph, fourth sentence: Potential confusing word
> "better". I suggest "Different techniques have been used to determine
> the number of atoms in both the targets with an uncertainty less than
> 0.1%"
>
> 22. Since we do not "show" it here, the last full sentence at the bottom
> of the first column should perhaps be an assertion: "The \omega
> photoproduction process ... is the dominant contribution to the
> background." (There was also a repeated word "the" in the text, by the
> way.)
>
> 23. Second column, first paragraph, second sentence: Remove extraneous
> commas: Two elementary amplitudes, the Primakoff (one photon exchange)
> T_Pr and the strong (hadron exchange) T_S, contribute coherently as well
> as incoherently in \pi^0 photoproduction from nuclei at forward angles."
>
>
> 24. In the next sentence, remove the unneeded capitalization:...
> "Primakoff (Pr), nuclear coherent (NC), interference (Int), and nuclear
> incoherent (NI):..." Also please note that we have not explicitly said
> at this point what is "interfering" with what; we chould perhaps say
> "interference between strong and Primakoff amplitudes (Int)" or add a
> sentence prior to this sentence that says "The Primakoff and strong
> interactions amplitudes will interfere, and that interference must be
> properly taken into account when calculating the differential cross
> sections."
>
> 25. A few sentences farther on, we write "photo-produced". Since we have
> not broken up the word anywhere else, we should simply write
> "photoproduced". In the same sentence, we should say "on" rather than
> "of", and can avoid the awkward "$\pi^0$s" by just saying either "pions"
> or "neutral pions". Thus, I would suggest: "The FSI effects on the
> photoproduced pions, as well as the photon shadowing effect in nucleare
> matter, need to..." At the end of that same sentence, we have several
> problems, so I would suggest that we write "...an extraction of the
> Primakoff amplitude with an uncertainly of better than one percent, and,
> therefore, the decay width." Thus, the whole sentence now reads: "The
> FSI effects for the photoproduced pions, as well as the photon shadowing
> effect in nuclear matter, need to be accurately included in the cross
> section calculations to provide an extraction of the Primakoff amplitude
> with an uncertainly of better than one percent, and, therefore, the
> decay width."
>
> 26. Column two, last paragraph, second sentence: use dashes to separate
> the parameters. Also, I would suggest rewording slightly to make things
> clearer: "In the fitting process, four parameters --- ...--- were varied
> to calculate the magnitude..."
>
> 27. The next sentence may confuse the reader as it stands. I would
> suggest "Multiple independent analyses of the experimental data by
> groups within the PrimEx collabration yielded the weighted averages
> presented in Table I for 12C and 208Pb."
>
> PAGE FOUR
>
> First column --
>
> 28. First line: Should read "...quoted total systematic uncertainty is
> the quadratic sum of all estimated uncertainties in this experiment."
>
> 29. Next sentence: "The systematic uncertainties.."
>
> 30. Second sentence: "...well-known processes..." and "...with the
> theoretical predictions..."
>
> 31. Last sentence: "Our result, with a total experimental uncertainty of
> 2.8\%, is the most precise measurement of the ... to date, being 2.5
> times more precise than the current average value quoted in the PDG [3]
> for this important fundamental quantity."
>
> Second column ---
>
> 32. Third sentence: "To assess the effects of chiral corrections to the
> anomaly, a measurement with a precision more than a factor of two better
> than the current measurement is required."
>
>
> -----Original Message-----
> From: primex-bounces at jlab.org [mailto:primex-bounces at jlab.org] On Behalf
> Of Ashot Gasparian
> Sent: Friday, July 09, 2010 9:45 AM
> To: primex at jlab.org
> Subject: [Primex] the latest version of the prl paper
>
>
>   Dear PrimEx Collaborators,
>
>   The latest version of the PRL draft is in the attachment.
>   It includes the most of suggestions done before yesterday
>   (Thursday) evening and it is formatted to fit 4 pages (it
>   was not an easy work).
>
>   This version does not include suggestions and comments received
>   from this morning (Friday). Many of them are very valuable
>   and we will try to implement them in the text.
>
>   Please keep commenting on the draft before Monday's Collaboration
>   meeting, where we intend to finalize the most part of the paper.
>
>   Regards,
>   Ashot
>
>
> .............................................................
> Ashot Gasparian                    Phone:(336)285-2112 (NC A&T)
> Professor of Physics
> Physics Department                       (757)-269-7914 JLab
> NC A&T State University              Fax:(757)-269-6273 JLab
> Greensboro, NC 27411               email: gasparan at jlab.org
> .............................................................
>