df7229 Brooks,T
Cyrus Taylor (cct@po.cwru.edu)
Fri, 30 Jul 1999 14:18:42 -0400
>Date: Fri, 30 Jul 1999 14:12:13 -0400 (EDT)
>From: prd <prd@aps.org>
>To: cct@po.cwru.edu
>Subject: df7229 Brooks,T
>
>
>Dear Dr. Taylor:
>
>
> The above manuscript has been reviewed by one of our referees.
>Comments from the report are enclosed for your consideration.
>
> When you resubmit your manuscript, please include a summary of
>the changes made, and a brief response to all recommendations and
>criticisms.
>
> Sincerely,
>
> John Ripka
> Assistant to the Editor
> Physical Review D
>-------------------------------------------------------------------------
>Referee report DF7229
>
>I have twice carefully read the paper, Search for disoriented chiral
>condensate at the Fermilab, Brooks et al., and I have looked at the key
>reference 6 cited in this paper. Perhaps a third reading would have
>brought answers to some remaining questions. Here follows comments and
>impressions.
>
>First of all, the paper is very well presented. Indeed it reads better
>than the majority of papers that I encounter. My inclination was not
>terribly great towards the physics in this study but the text kept me
>involved. They do a particularly good job of presenting the problems
>encountered. Since physicists spend the majority of their time on things
>that didn't work properly or on limitations encountered during the course
>of an experiment, this is most appropriate; yet it is still quite rare.
>The authors should be applauded for this aspect of the work.
>
>The paper presents new results and it therefore should be published, in
>PRD.
>
>Here I make some specific comments and suggestions (in no particular
>order) that I would like to see the authors respond to.
>
>1. The authors begin by introducing the expected P(f) for a DCC state. It
>would be good if they could present the distribution they have found, or
>at least one that is consistent with their data. Can they not unfold this
>distribution? Is the neutral pion fraction indeed 1/3?
>
>2. The authors should clarify a seeming discrepancy regarding event
>rates. They state (on page 6) that their trigger cross-section was 43 mb.
>The lowest luminosity they appear to have run at for the 6 day run seems
>to be of order 10**28 /cm**2/sec. This would imply a trigger rate of 430
>Hz so that they could collect all their 1.3M events is less than one hour.
>Even given modest dead-times, I don't see how they could have taken 6 days
>worth of data. The reported trigger rates don't seem to make sense either.
>
>3. A concern remains with this reader about how valid the results are,
>given that they have trouble simulating their backgrounds. Have they made
>any attempt at superposing additional hits on their simulated events and
>then testing whether their novel statistics change significantly? As I
>understand it, after cuts their simulation reproduces track and photon
>distributions [see comment 8 below] but it fails to reproduce lots of
>extra hits away from tracks. True? (If so, this is not uncommon or
>unexpected.)
>
>4. I don't understand the statement on page 14 that the deviations from
>unity for the higher order ratios in Table VII are not very significant.
>The reported values are FAR more significantly different from 1.0, using
>the quoted errors, than are those for the low order ratios. Perhaps when
>normalized to their monte-carlo, this effect goes away but the authors
>give no indication of that.
>
>5. The authors claim that the low-order ratios for diffractive and
>forward tagged events are consistent with those from the total sample. Yet
>in every case, the numbers are greater in these samples than in the total
>sample; and this tendency continues for the higher order ratios as well.
>And by the way, does the simulation give the correct fractions of events
>for these tagged samples?
>
>6. At the bottom of table VII are found the values for the low order
>ratios using the alternative tracker. The event total just above the
>bottom three entries seems to be those found with the alternative tracker.
>If so, this should be stated somewhere; and then it needs to be explained
>why this tracker seems to be only 18% as efficient as the nominal one.
>This is doubly puzzling in that the other subsamples that are called out
>(diffractive, forward) have comparable event totals for the two trackers.
>
>7. The technique of using ratios of factorial moments seems to allow
>extraction of the physics without the need to worry about things such as
>tracking efficiency, etc. But what information is lost? I.e., if one did
>fully understand efficiencies, could more be learned?
>
>8. I don't understand what conclusions are to be drawn from Figure 8.
>Is it that the simulation gets the normalization and distribution of
>charged and neutral particles correct at the 10% level? This would follow
>if the simulations include detector effects which they no doubt do. If
>so, the authors should state this as it gives important validation of
>their simulation procedure and of their understanding of their analysis
>and cuts. Also, the large shift between PYTHIA and GEANT for the photon
>distribution, no doubt having much to do with conversion probability,
>should be explained in the caption (or in the text).
>
>9. Finally, there is no clue as to why the experiment is called
>"MiniMax."
>-------------------------------------------------------------------------
>
>
> ********** Manuscript ******************
>
> DF7229 D1-1
> Search for disoriented chiral condensate at the Fermilab
> Tevatron
> Brooks,T.C./Convery,M.E./Davis,W.L./Del Signore,K.W.
>
>
> ****************************************
>
-----------------------------------
Cyrus Taylor (216) 368-3710
Armington Professor (216) 368-4671 (FAX)
Department of Physics cct@po.cwru.edu
Case Western Reserve University ctaylor@fnal.fnal.gov
Cleveland, OH 44106-7079
USA