Hi All, I attach here the dpAuAu paper with the modifications that address the referee comments (magenta) I have also added a few more references. Please read it and let us know your opinion. Flemming will do some additional work in the blue sections. Ramiro On Sep 16, 2010, at 7:38 PM, Ramiro Debbe wrote: > Hi All, > I have placed the dp paper and it possible modification in the Indico page. I have not had enough time to finish what I wanted to accomplish but I wrote some lines that we can discuss tomorrow. > Ramiro > On Sep 2, 2010, at 10:05 PM, Ramiro Debbe wrote: > >> Hi All, >> I have placed the dp paper in the Indico agenda for tomorrow's meeting. The paper has Flemming's comments (blue) as well as a new version of the figures, and my comments (magenta). >> Thanks, >> Ramiro >> On Sep 1, 2010, at 9:14 PM, Ramiro Debbe wrote: >> >>> Hi All, >>> I added some suggested changes to the dp paper to accommodate the referee comments (I used my old magenta color to highight that text). I was unable to see if I can still build the pdf version because rcf2 is not working well and I did my work on an rcas machine. I committed the changes back to CVS. Hopefully I can generate a pdf version before the meeting on Friday. >>> Ramiro >>> On Aug 24, 2010, at 12:44 PM, Ramiro Debbe wrote: >>> >>>> Hi Michael, >>>> I was very exited when I saw the extent of the referee comments and started looking at possible actions, I think we can improve the paper greatly. >>>> I went thru some of our references, found a few new ones, mainly looking for a more recent point of view and I asked around (mainly about comment 5) >>>> I add some suggestions after the referee comments. >>>> Ramiro >>>> On Aug 6, 2010, at 5:20 PM, Murray, Michael J wrote: >>>> >>>>> FYI >>>>> >>>>> >>>>> Michael >>>>> >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: prc_at_aps.org [mailto:prc_at_aps.org] >>>>> Sent: Fri 8/6/2010 12:48 PM >>>>> To: Murray, Michael J >>>>> Subject: Your_manuscript CS10219 Arsene >>>>> >>>>> Re: CS10219 >>>>> Rapidity dependence of deuteron production in Au+Au collisions at >>>>> sqrt s NN=200 GeV >>>>> by I. Arsene, I. G. Bearden, D. Beavis, et al. >>>>> >>>>> Dear Dr. Murray, >>>>> >>>>> The above manuscript has been reviewed by one of our referees. Comments >>>>> from the report appear below. >>>>> >>>>> These comments suggest that specific revisions of your manuscript are >>>>> in order. When you resubmit your manuscript, please include a summary >>>>> of the changes made and a succinct response to all recommendations or >>>>> criticisms contained in the report. >>>>> >>>>> Yours sincerely, >>>>> >>>>> Bradley Rubin >>>>> Senior Assistant Editor >>>>> Physical Review C >>>>> Email: prc_at_ridge.aps.org >>>>> Fax: 631-591-4141 >>>>> http://prc.aps.org/ >>>>> >>>>> Physics - spotlighting exceptional research: http://physics.aps.org/ >>>>> >>>>> PROBLEMS WITH MANUSCRIPT: >>>>> >>>>> In reviewing the figures of your paper, we note that the following >>>>> changes would be needed in order for your figures to conform to the >>>>> style of the Physical Review. Please check all figures for the >>>>> following problems and make appropriate changes in the text of the >>>>> paper itself wherever needed for consistency. >>>>> >>>>> Figure(s) [4] >>>>> Please rearrange power of 10 in axis label for clarity: Either >>>>> (i) place the power of 10 as a factor, without parentheses, >>>>> in front of the axis label quantity, changing the sign of the >>>>> power as needed; or (ii) incorporate the power of 10 in the >>>>> topmost or rightmost number on the scale. Please refer to >>>>> the URL http://forms.aps.org/author/h18graphaxislbls.pdf for a >>>>> pictorial representation of the preferred forms for axis labels. >>>>> >>>>> Figure(s) [please check all and amend where necessary] >>>>> The lettering in the axis labels and/or numbering size should be >>>>> increased. Please ensure that all lettering is 2 mm or larger >>>>> (1.5 mm for superscripts and subscripts) after scaling to the >>>>> final publication size. Note that the column width is 8.6 cm >>>>> (twice that amount plus gutter for extra wide figures). >>>>> >>>>> >>>>> Please remove the redundant arXiv references for published papers. >>>>> For your information, the editorial office checks the references at >>>>> several crucial steps during the editorial process. A list of unnecessary >>>>> arXiv references slows the process down considerably--particularly so, >>>>> if the list is long--and delays the processing of your manuscript. >>>>> >>>>> Please note that the copy editors will remove such redundant links during >>>>> production for those papers that have been accepted for publication. >>>>> However, any manual intervention carries the risk of inadvertently >>>>> introducing mistakes. >>>>> >>>>> ---------------------------------------------------------------------- >>>>> Report of the Referee -- CS10219/Arsene >>>>> ---------------------------------------------------------------------- >>>>> >>>>> Executive Summary: >>>>> ----------------------------------------- >>>>> The paper is a straightforward, almost minimalist, presentation >>>>> of a data set on proton and deuteron production in central Au+Au >>>>> RHIC collisions over a wide range of rapidity, and antiproton and >>>>> antideuteron production over a smaller range in rapidity. The >>>>> data are interpreted in terms of a standard coalescence picture >>>>> and an extracted phase space density; some trends are noted but >>>>> no definite physics conclusions are drawn. As a simple data >>>>> presentation exercise the paper is generally acceptable, though >>>>> the physics impact of the data are significantly limited by >>>>> being restricted to only central collisions in only one bin of >>>>> centrality. >>>>> >>>>> Though I would not suggest it as a requirement for publication >>>>> in the Physical Review, I would urge the authors to consider >>>>> enlarging the paper to include data from a greater range of >>>>> centrality classes -- based on the error bars shown in Fig 5 >>>>> it certainly looks as though sufficient statistics would be >>>>> available. >>>>> >>>>> Modulo that decision, the paper has a number of minor errors >>>>> in the physics introduction which should be addressed, as >>>>> detailed below. My basic recommendation, then, is that the >>>>> paper will be suitable for publication with minor corrections. >>>>> >>>>> >>>>> Concerns: >>>>> -------------------------------------- >>>>> (1) Centrality selection. The data presented in Fig 3 are for some >>>>> particular event selection; but which? One needs to scan the >>>>> paper in some detail (or use a computer text search) to find >>>>> the lone sentence "We present ... AuAu collisions with a centrality >>>>> range of 0-20%." in the first paragraph under Section II. Analysis. >>>>> (Note that this sentence itself is not quite grammatically correct.) >>>>> >>>>> Physics: Why was this one, and only one, centrality range chosen >>>>> for this analysis? There is no motivation mentioned in the paper >>>>> at all, which is quite puzzling. The paper describes interpretation >>>>> in terms of geometrical quantities such as the coherence volume implied >>>>> by the B_2 measurement; it is only natural to ask, then, how these >>>>> might change as the collision geometry/centrality is changed. To >>>>> present data from only one centrality selection, with no explanation, >>>>> seems quite odd and un-natural, and I would call it a glaring defect. >>>>> There is of course a limit on available particle statistics, but it >>>>> is far from clear (partly because there is so little detail provided >>>>> on the error analysis) that no statement could be made for any other >>>>> selections, even by breaking the current one into two. >>>>> >>>>> Analysis: The section on the data analysis should include a description >>>>> of how the events were selected on centrality. >>>>> >>>>> Formatting: Assuming that the paper is to be published on just the >>>>> central collision results, that fact should be made clear throughout >>>>> the work: it should appear in the title, in the abstract, in the >>>>> summary and in the captions of all the figures and tables. And, >>>>> for that matter, the main data graphs such as Fig 3 should also >>>>> state that these results are for the Au+Au collision system! >>>>> >>>>> >>>>> (2) Error analysis. The presentation in Table I does a good basic job >>>>> of explaining the uncertainties: statistical errors are in the table, >>>>> systematics are characterized in the text. All of the figures and >>>>> tables should rise to this same standard: what is shown by the errors >>>>> that are displayed? and what are the sizes of the other sources? >>>>> >>>>> Elsewhere the treatment of uncertainties is uneven. The discussion >>>>> of errors from the feed-down correction in Section II.D is quite >>>>> quantitative; while the preceding section II.C on particle >>>>> identification describes inefficiencies and contaminations, but does >>>>> not quote anything quantitative for the residual uncertainties from >>>>> these effects. At a minimum the reader should be able to appreciate >>>>> the relative contributions of statistical versus systematic >>>>> uncertainties, and what the dominant source is for the systematic, >>>>> for every quantity quoted and plotted in the paper. >>>>> >>>>> >>>>> (3) Abstract: "in contrast to lower energy data". This should be >>>>> re-worded to make clear that it refers to data from collisions >>>>> at lower collision energies, rather than lower secondary particle >>>>> energies. >>>>> >>>>> (4) p1 col2: "surrounding ... medium ensure energy and momentum >>>>> conservation". "Ensure" would be better as "allow" or "permit" >>>>> or "enable". Conservation laws always "ensure" that they are >>>>> followed; the role of the medium is to "allow" p + n -> d >>>>> to proceed without the need to emit a photon. >>>> >>>> I suggest to change the sentence: "In free space ....." by the following >>>> "The surrounding medium created in the A+A collisions enables this 2->1 process to >>>> proceed while it conserves energy and momentum." >>>>> >>>>> >>>>> (5) p1 col2 "As deuterons are formed inside the expanding system" >>>>> Is this really true? How do you know? One could make the simple >>>>> argument that particle within the medium are colliding often >>>>> enough, on the order of once per ~1-10 fm/c or faster in the time >>>>> before freezeout, then the constituent protons and neutrons will >>>>> on average be off their mass shell by ~200-20 MeV at any given >>>>> moment; if this is true, then how can one even distinguish a >>>>> deuteron bound state, whose binding energy is only 2 MeV? >>>>> The bound/unbound distinction doesn't apply over such short >>>>> time scales. >>>>> The same misconception appears later in the same paragraph >>>>> with the phrase "deuterons are most likely formed very near >>>>> freeze-out". What, exactly, does "formed" mean here? In order >>>>> for a p,n pair to be meaningfully distinguished as either bound >>>>> or unbound, the degree to which they are off-mass-shell must be >>>>> no larger than the bound-state binding energy. This implies that >>>>> bound-state deuterons cannot even be _defined_ until ~100 fm/c >>>>> have passed since the particles' last momentum transfer >>>>> interaction, ie freezeout; this time frame cannot be described >>>>> as "very near freezeout." It really makes no sense to say that >>>>> deuterons are "formed" on a timescale faster than they can even >>>>> be distinguished or defined, whether inside the colliding system >>>>> or following freezeout, so this whole passage of the >>>>> introduction is really misconceived. >>>>> The reason that sudden-approximation coalescence models can >>>>> work is more subtle, quantum mechanically. After the last >>>>> momentum exchanges, ie freezeout, all the protons and neutrons >>>>> will be in wavefunctions which span a range of masses around >>>>> their free-particle on-shell rest mass. The off-shell >>>>> combinations of momentum and energy will decay away with time, >>>>> ie the amplitude of those parts of the wavefunctions will >>>>> diminish and only the on-shell states will have significant >>>>> amplitudes. So, looking into the future at the time of >>>>> freezeout it is reasonable to count only the on-shell states >>>>> for future accounting purposes; but the off-shell states are >>>>> still present in the wavefunction at that time. >>>>> For this reason, one can get reasonable answers from a >>>>> coalescence model while neglecting these off-shell subtleties. >>>>> But, by the same token, there is no excuse at this point in >>>>> the field for leaving a sloppy definition of "formed" in the >>>>> introduction to a paper like this, and the section should be >>>>> rewritten without this misconception. >>>>> >>>> Even though recent publications (PHENIX) use similar language, I detect a consensus >>>> in the papers I read but mostly from the responses I get when I asked other >>>> colleagues with experience in the subject. I suggest we state the following and add a recent paper: >>>> >>>> In the hot and dense system formed in high energy collisions, the coalescence of nucleons into deuterons >>>> is not possible before it reaches a stage where hadrons are present, and even then, the low binding energy of deuterons (2.24 MeV), >>>> force this process to happen only late, near the so called thermal freeze out, where the nuclear density is low but still high enough to allow >>>> for interactions that put all participants back on mass shell. \cite{Ioffe} >>>> >>>>> >>>>> (6) p1 col2: "Coalescence models assume that the distribution >>>>> of clusters..."; "density" or "phase-space density" would be >>>>> better than "distribution" >>>>> >>>>> >>>>> (7) p1 col2 and Eq. 1: The references [1-3] quoted to >>>>> introduce the notation of the coalescence picture in Eq. 1 >>>>> are incomplete; they date from the Bevelac era (or earlier), >>>>> when the notation C_2 was used for the proportionality >>>>> similar to that in Eq. 1 but with cross sections rather than >>>>> per-event densities. The B_2 notation used here was originated >>>>> during the AGS fixed-target heavy-ion program, starting with >>>>> E858 and then E864 and E878; and it is a rather glaring >>>>> omission that not all of these experiments are referenced in >>>>> this paper, which should be corrected. >>>>> >>>> We could drop the 1-3 or add to them a more recent review: L.R.Csernai, J.I.Kapusta, Phys. Rep. 131, 223 (1986); >>>> We should add the E858 E864 and E878 references. >>>>> >>>>> (8) p1 col2: Mention is made of the n/p ratio in lower-energy >>>>> collision data, but the meaning and significance are not clear >>>>> at all. What system was this for? Does this n/p ratio >>>>> correspond to that of the incoming nuclei, or not? Is the >>>>> implication that Eq. 1 should be modified, or assigned a 20% >>>>> systematic error? If not, why not? The bare inclusion of >>>>> this observation, without any details, explanation or >>>>> implication is simply confusing and not helpful to the reader. >>>>> >>>>> >>>>> (9) p2 col1: "B_2 carries information about the cluster" >>>>> What do you mean by "cluster"? Is it the deuteron itself, as >>>>> implied on the previous page with the phrase "the distribution >>>>> of clusters"? Or does "cluster" mean the system as a whole? >>>>> Neither really makes sense; B_2 doesn't really tell you >>>>> anything about the deuteron itself per se; and it's strange, >>>>> as well as inconsistent with the previous page, to refer to >>>>> refer to the whole system as a "cluster". >>>>> >>>> This sentence now reads bad. B_2 is related to the volume of the source of deuterons. For a while >>>> we tried to be general and used clusters to include d, He3, and other heavier systems, I suggest to remove >>>> the word cluster and replace by deuteron. And rewrite this sentence: effective volume of the nuclear matter at the time of coalescence >>>> >>>> In thermodynamical models that assume thermalized distributions of nucleons, B2 carries information about the effective volume of the nuclear matter at the time of coalescence: >>>> [1–3]. >>>> >>>> more comments below point to our confusion of of coalescence volume and deuteron source volume, we should just keep coalescence volume. >>>> >>>>> (10) p2 col1: "B_2 ... is consistent with measurements of >>>>> the deuteron wave-function." This is a very strange and >>>>> jarring statement to read at this point in the paper, since >>>>> there has been no discussion up to this point on how the >>>>> deuteron's spatial properties figure into the value of B_2 >>>>> through the coalescence process or otherwise. >>>> >>>> We need to move the next sentence where we mention the Wigner functions up before this discussion. >>>> By the way, the sentence mentioning Wigner functions is describing a particular case of sudden-approximation coalescence model. >>>>> >>>>> (11) Also, this statement is referenced to Ref 5, but only >>>>> vague mention is made of what collision systems or what >>>>> collision energies are being referred to; this makes it >>>>> somewhat strange to read in the very next sentence that >>>>>> = 4.9 GeV is the threshold of "high energy". It would >>>>> be clearer to state the energy ranges, and at least whether >>>>> heavy or light nuclei are involved, for all the data being >>>>> referred to (this remark applies in several other places >>>>> throughout the current paper, as already mentioned in >>>>> point 8 above). >>>> >>>> Needs work >>>>> >>>>> (12) p2 col1: "assuming the region where the coalescence >>>>> occurs has also a Gaussian shape" See point 5 above; the >>>>> region which sources/radiates the nucleons is not the same >>>>> thing as the region where coalescence occurs. Note also >>>>> that "spatial profile" would be better than "shape" in >>>>> this sentence. >>>>> >>>>> (13) p2 col1: "this ansatz ... facilitates comparison to >>>>> interferometry radii". A traditional point; but, how does >>>>> the comparison work in this case? First, should the R_G >>>>> from the coalescence framework analysis be compared >>>>> directly to any of the R parameters from HBT analysis? >>>>> or is there a factor of 2, or pi, etc between them? >>>>> Is this paper going to actually make the comparison? >>>>> if not, then you should provide a reference to how the >>>>> comparison should be done. >>>>> >>>> Shall we try that comparison? >>>> >>>>> (14) p2 col1: "However, it has been suggested that..." >>>>> This certainly needs a reference, or several, at this point. >>>>> >>>> I agree we need that reference. Voloshin? >>>> >>>>> (15) p2 col1: The middle paragraph discusses the results >>>>> of deuteron production following a quark coalescence picture, >>>>> which is a subject of considerable current interest. However, >>>>> the logic is not laid out clearly here. Isn't it true, for >>>>> example, that if protons follow the quark coalescence picture >>>>> and deuterons follow the nucleon coalescence picture, then >>>>> deuterons automatically/necessarily follow quark coalescence >>>>> as well? ie isn't quark coalescence for deuterons redundant >>>>> with nucleon coalescence? and so not really an independent >>>>> piece of information. Alternatively, is the statement that >>>>> deuterons follow quark coalescence equivalent to B_2 being >>>>> constant with pT? But here B_2 is not constant with pT, as >>>>> we see in Fig 4; doesn't that have immediate implications for >>>>> quark coalescence interpretation of the present data? >>>>> In general this section should be written so as to make >>>>> it clear to the reader what are, and are not, redundant versus >>>>> independent pieces of information. >>>>> >>>> This requires reading the references we will add to accommodate comment 14 >>>> >>>>> (16) p2 col1: The start of the discussion of discussion of >>>>> phase-space densities in the last paragraph should have at >>>>> least a few references right at the beginning, especially >>>>> as to the motivations. Why is this an interesting quantity? >>>>> The text mentions (i) an indicator or measure of the degree >>>>> of equilibrium, which is directly connected to entropy, >>>>> and (ii) "information about ... symmetrization efects". >>>>> Reasonable enough; but what's the upshot? What do the results >>>>> shown in Fig 5 demonstrate? Trends are noted in Section III, >>>>> but what about the basic magnitude of the measured quantity? >>>>> is it high, is it low? >>>>> >>>> It is low! but I agree we could invest more effort here. It will also add to the summary section. (More reading to be done) >>>> >>>>> (17) p2 col2: The result of Eq. 5 is correct only for a true >>>>> global equilibrium, with one universal temperature and where >>>>> the particles have equal access to the entire relevant volume. >>>>> The text acknowledges this, but only in a roundabout way with >>>>> the later remark "we are ignoring the collective motion of the >>>>> particles", as collective motion is a departure from true >>>>> global equilibrium (also, "neglecting the possibility of" is >>>>> more accurate than "ignoring" here). But since collective >>>>> motion probably is the case in RHIC Au+Au collisions, from the >>>>> B_2 results shown here as well as a host of other evidence, >>>>> it is left unclear to what extent Eq.'s 5 - 9 should still be >>>>> considered relevant. For example, in the statement farther down, >>>>> attributed to Ref 23, that strong longitudinal flow could >>>>> significantly reduce pion phase space densities, it is not clear >>>>> if this is a true result about the actual density or an artifact >>>>> of Eq. 5 and its corollaries being invalid in the extraction of >>>>> the measured phase-space density. >>>>> In general the utility of a framework which assumes global >>>>> equilibrium to a system which probably exhibits only local >>>>> equilibrium needs to be explained more carefully; if T is a >>>>> function of space, then is Eq. 5 still true at a point? In >>>>> the case of collective motion being significant, is Eq. 3 >>>>> defined over some relevant coherence volume? etc. >>>> >>>> Needs work >>>>> >>>>> (18) p2 col2: "the maximum space averaged phase-space density, >>>>> which is at the center of the Gaussian source." Sorry, but >>>>> this makes no sense at al: a spatial average is not defined >>>>> for different points within the space. The confusion over >>>>> the relevant spatial volumes mentioned in point 17 above >>>>> is clearly causing serious trouble here. >>>> >>>> Need to read Pratt paper ref[26] >>>>> >>>>> (19) p2 col2: In Eq. 9, is R_G a function of particle >>>>> momentum, particularly pT? Presumably so, and if so then it >>>>> would be useful to write the dependence explicitly here. >>>> >>>> According to eq.2 we should make R_G pt dependent. >>>>> >>>>> (20) Minor formatting: the text following Eq. 5 should >>>>> probably be left-justified rather than indented. It is not >>>>> clear whether the text following Eq.'s 4 and 6 should or >>>>> should not start new paragraphs, either. >>>>> >>>>> (21) The presentation of Eq. 6 in terms of chemical potential >>>>> is formally correct, but at the same time obscure -- in the >>>>> dilute limit, what is the value of these chemical potentials? >>>>> Is it just the particle mass, which would make Eq. (6) >>>>> equivalent to exp[-mT/T] at all rapidities? or does it vary >>>>> significantly with the net baryon density, which changes >>>>> considerably with rapidity (as BRAHMS has made clear in >>>>> other measurements)? >>>> >>>> We need to go back to the text book. >>>>> >>>>> (22) p5 col2: "expect the ratio of the proton and antiproton >>>>> phase densities to be flat"; is this as a function of >>>>> rapidity? or pT? or both? >>>>> >>>>> (23) Summary, but also relevant to several sections of the >>>>> paper: There is a reasonable interpretation here that the >>>>> B_2 and phase space density measurements have information >>>>> about the existence of collective flow, particularly what >>>>> is called radial flow. This is certainly valuable and >>>>> worth publishing. However, the current paper doesn't say >>>>> much about whether these implications are or are not >>>>> consistent with the great body of work that has now been >>>>> done on modeling RHIC A+A collisions with hydrodynamics. >>>>> It is not necessarily the responsibility of this paper >>>>> to make a full-blown analysis, but the reader deserves some >>>>> basic orientation: are the results shown here generally >>>>> consistent with existing hydrodynamical models? or is >>>>> there some kind of surprise or contradiction brewing? >>>>> >>>>> >>>> We knew our physics points were weak. >>>>> _______________________________________________ >>>>> Brahms-dev-l mailing list >>>>> Brahms-dev-l_at_lists.bnl.gov >>>>> https://lists.bnl.gov/mailman/listinfo/brahms-dev-l >>>> >>> >> > _______________________________________________ Brahms-dev-l mailing list Brahms-dev-l_at_lists.bnl.gov https://lists.bnl.gov/mailman/listinfo/brahms-dev-lReceived on Thu Sep 23 2010 - 21:04:31 EDT
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