[Clascomment] Pereira et al K+ Sigma paper

[Reinhard Schumacher]

Dear Anefalos,

	Here are my comments to your remarks.

	I remain of the opinion that to make this paper stronger, and more 
likely to get accepted for publication, some improvements ought to be 
made.  Whether or not to back up at this stage and make them, I will let 
the Ad Hoc committee decide (it is their job).

	The original comment I made about the data being very nice still 
stands:  within the Collaboration you have shown your work and had the 
usual reviews to give everyone confidence in the results. My later 
comment about the results being "probably" fine is when I take the point 
of view of a reader of your paper.  Is the paper *convincing* as it 
stands?  I think there are weak points.  My criticisms of your paper 
stem from places I think an *outside reader* may come to doubt the 
reliability of the work.

	The first place is in Figure 1, where you did not justify in the paper 
the seemingly arbitrary cut of the data on the left side of the peak. 
Of course your results will not change if the Monte Carlo is in good 
shape, but just ask yourself what a reader thinks when he or she sees 
that figure and reads the associated text.  The text does not say, for 
example, the explanation you gave to the Collaborators who commented on 
this point.  This could be added to the text.

	The second place is in Figure 2, for which the arbitrariness of using a 
Lorentzian line shape is not justified in the text.  Even if it "fits 
the data better" does not mean it is correct.  If it is indeed the case 
that the Monte Carlo distribution looks the same (I assume you convinced 
the technical review committee of this), then it would help to at least 
*say* that.   Even better would be to overlay the Monte Carlo 
distribution on the data in Figure 2.

	The third place is in Figure 3 where the results are presented.
It seems to me you are giving away an opportunity to show the results to 
best advantage by not showing and discussing the small cross section at 
backward angles.  This would be most easily approached by at least 
plotting the high E_gamma results on a semi-log scale.  It seems you are 
not interested in doing this, at least not in this paper.  Perhaps you 
could at least *say* that you plan to investigate this in the future, an 
make reference to the "to be published" paper that you have have told us 
you plan to write.

	The last place I feel the paper could be better is to take J.M. Laget's 
comments to heart and give some quantitative estimates of the size of 
FSI that would be needed to convert the present results to the true 
elementary cross sections.  The reader has no idea how big these effects 
are:  0.5%, 5%, 50%?  Are the corrections well understood or out of 
control?  I am surprised you did not take up his offer to help on this 
point.   This would be another place where the reader of this paper 
would get a better understanding of the significance of your results.

	OK, that is enough for now.  Please consider these remarks once again 
and decide what you want to do.

Best Regards,
Reinhard

________________________________________________________________________
Reinhard Schumacher                            phone: 412-268-5177
Department of Physics, 5000 Forbes Ave.        fax:   412-681-0648
Carnegie Mellon University                     email: schumacher at cmu.edu
Pittsburgh, PA 15213, U.S.A.         web: www-meg.phys.cmu.edu/~schumach
________________________________________________________________________









Such a reader has not seen all the effort that went into your

anefalos at jlab.org wrote:
> Dear Reinhard and Ad Hoc committee members,
> 
> After receiving this email message from Reinhard by the end of last year
> we have decided to answer as soon as possible. Because of end-of-year
> holidays  it was possible only today. The comments were divided by
> subjects and answered separately.
> 
>> Hi All,
>> I would like to hear from the Ad Hoc committee directly about this paper.
>> It seems to me that the many comments of the collaborators have not been
>> treated with due respect and consideration.
> 
> We are very surprised reading this as we believe we've answered all
> questions with respect and consideration as can be seen in the CLAS
> comment site. In particular, we have accepted almost all remarks/comments.
> The very few that have not been accepted  were due to two reasons: 1)
> there were conflicting arguments between two or more reviewers and we had
> to  choose just one of them, and 2)  we do not agree with the reviewer's
> argument and we tried to explain why.
> 
>>  The lead authors
>> have dismissed most of the substantial comments without  offering
>> discussion and explanation beyond, in essence, repeating that they are
>> satisfied with their own work as it stands.
> 
> On the light of our previous answer we do not understand your complain. 
> Could you please explicitly state which comments we didn't offer any 
> explanation?
> 
>> As it stands now, the results of the paper are *probably* fine, but an
>> outside reader of this paper is, in my view, not going to be convinced.
> 
> We completely disagree with your statement where, moreover, you also
> contradict yourself. In fact, in your last email you said  "My overall
> impression is that the data look good and I am very glad  that CLAS is
> finally going to publish
> something useful on strangeness production off a deuteron target.  We 
> have been promising this for too long a time.  But now you have a nice 
> result...." and now you state that the results
> of the paper are *probably* fine. We would like to know what made you 
> change your opinion.
> Moreover and more important, all our results and analysis procedure have
> been approved by the Analysis Review Committee. The paper has also been
> approved by the  Ad Hoc review committee. It was a long interaction period
> when all the questions were discussed and our work was largely improved.
> Unless both  committees were wrong, the word *probably* does not fit well
> here.
> 
>>   We undercut our own case by (i) not showing (some of) the data on a
>> log scale to look for "structure",
> 
> As clearly stated in our previous replay posted available on the comment
> site, showing some of the data in log scale to look  for "structure" will
> improve the understanding at large backward angles  *but* it would make
> the forward region worse. Moreover, the statistical errors of points at
> backward angles would make any physical interpretation complicated. Please
> have a look at the attached table where you can find  all the cross
> section values and their corresponding statistical errors.  In the first
> column you find photon energy (GeV), in the second is cross section and in
> the third the error. For every photon energy bin there are 20 values for
> the cross sections. They are the 20 bins of cos(Theta) from -1 to 1.
> 
>> (ii) not discussing some of the
>> systematic issues and cut selections (various peoples' comments),
> 
> Did you read our answer (related to the proton missing mass cut)? Making 
> the cut wider we would increase only the amount of background that will 
> be removed in the following analysis. In the end the results will be 
> exactly the same. Please have also a look at the analysis note (chapter
> 5.4.  and Appendix F). Concerning the use of a Lorentzian, our first try
> was  with a Gaussian function, but it didn't describe the data very well. 
> Following the analysis review committee suggestion a Lorentzian was used 
> and the agreement improved significantly. The Lorentzian fits very well 
> both, the data and the Monte Carlo, distributions.
> You also say that these issues came from "various peoples' comments". We 
> could only find two people comments on that: - Kei Moriya and yourself.
> Could you  tell us who else expressed doubts about systematic issues and
> cut  selections?
> 
>> (iii) not including a comprehensive discussion of available models and
>> interpretive issues (see comments by JM Laget).
> 
> As we stated before, and is stressed in our paper title, we are
> presenting cross section results on a *bound* neutron. The model we've 
> compared with our results is the ONLY published one that predicts some 
> results on neutron. NO other models that we can mention with
>  references are available on the market. Moreover, simply adding a phrase
> saying "A  comprehensive treatment of FSI and the extraction of the
> neutron cross  section will be given in the forthcoming longer paper.", as
> suggested by Laget, would make our  paper lose strength, giving a chance
> to someone ask "Why don't you wait and publish also the results for a free
> neutron (that is including FSI) in only one paper?".
> 
>> These are important issues.  I want to hear form the Ad Hoc committee
>> whether they believe this paper is sufficiently good to be accepted by
>> Physical Review Letters... and why.  If they cannot or will not comment,
>> I think the Coordinating Committee should take this up.
> 
> Since the beginning, the paper has been examined by the Ad Hoc committee
> for submission to PRL. Again, we have already answered this question.  We
> think the paper meets the PRL requirements. It presents the first
> measurement of strangeness photoproduction cross section on the neutron in
> a wide angular and photon energy range: the results are very interesting, 
> not only in the specific subfield, but also for a more general audience as
> they will significantly constrain  theoretical models on hyperon
> photoproduction and possibly shed new light in the structure of the
> nucleon. So we should aim for PRL. In the case the PRL Editor will
> consider the paper of not very broad interest, he will automatically
> transfer it to PRC Rapid Communication together with the referee's review
> and we should not loose any time. By the way, please notice that this
> extra reviewing round you have requested (despite the decision of the Ad
> Hoc committee to go ahead), is already delaying the publication of the
> manuscript.
> 
>> Regards,
>> Reinhard
> 
> In conclusion, we believe we've answered all comments with respect and 
> consideration in a satisfactory way. We hope that now all open questions 
> and doubts have been cleared.
> 
> Best regards,
> Sergio
> 
> 

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