=========================================================================== ARGONNE Comments =========================================================================== Argonne, 27-MAR-1996 Here are the Argonne comments as of today. (Not all parties have been heard from, so if I collect any more comments before Friday, I'll send an appendix) Tom -------------------------------------------------------------------- Page 5: The CMU chambers are not behind 5-9 interaction lengths of material. They are behind only ~5 interaction lengths. >> OK. Fixed. Page 9: 95.5 +/- 14.3 events should be 96 +/- 14. I'll give you one more decimal place than strictly allowed, but I draw the line at two. >> There is some difference of opinion as to what is correct, in this >> situation. One of the authors believes strongly that we should keep >> the three significant figures as it is an intermediate result that is >> used later on. Page 19: Section C: I don't understand this at all. In the section before we find f_d/f_u, and f_s/(f_u+f_d). Now, as far as I can tell, we add the constraint f_u + f_d + f_s + f_Y = 1, and take the baryon fraction f_Y from some other experiment and solve three equations in three unknowns. Is this it? Does this warrent a whole new section? Shouldn't it just be one more sentence after the ratios? >> The calculation, to be done properly using the constraint of sum f_i =1.0, >> should be put into the form we present, which we don't believe is obvious >> to the casual reader. The issue is that we estimate the ratios of >> the f_i and not the absolute values, and it is in that form where the >> systematic uncertainties cancel maximally. Thus, we believe it is >> important to give the details. >> >> We also believe that this section should be set off from the other >> one because to make this calculation, we have to use a value for f_Lambda, >> whereas before we did not. We think it is clearer presented separately. The theoretical comparison that follows (page 21) is all about the ratio of f_s to f_u and f_d, right? Shouldn't this then be in the previous section? >> Yes, you are quite right. We have moved this paragraph to the end of >> the previous subsection. =========================================================================== LBL Comments =========================================================================== Here are comments from LBL on the paper "Ratios of b quark fragmentation probabilities and bottom meson branching fractions involving j/psi mesons". We congratulate the authors on the good work that has gone into this paper. We also note that the English is quite reasonable, so that we are able to focus on questions of presentation and physics. General Comment: We are somewhat confused on the main aim or thrust of the paper. Essentially, there are measured quantities and there are derived quantities. But the distinction in the paper is very blurred. For example, if a PDG person, or someone giving a talk on B decay br's, reads the abstract (or title) will it be clear that some measured (not derived) quantities are being presented? Section V, on results, combines both. And Table IV, which gives the measured quantities, contains the words "fragmentation fractions" in the title, which may well give a reader the impression that these are derived quantities. It seems to us that what is measured, the 5 cross sections times branching ratios, should be clearly stated, in Abstract and in its own section. These measured quantities presumably are good for many years, belong in compilations etc. The derived quantities, i.e., the fragmentation probs. and the absolute br's, depend on world averages and models which will surely change with time. >> The Results section is organised in the manner suggested by this >> comment. In fact, the "measured quantities" are the ratios of the >> branching fractions times fragmentation fractions and not the five >> cross sections times branching ratios the reviewers refer to. These >> measured ratios are equal to ratios of fragmentation fractions times ratios >> of branching fractions. The fact that the measured values are in >> fact products of two quantities is not something we can change. Detailed comments. 1. We are unhappy with the Title, but do not have any great alternative. Unless it just says that several B meson cross section times br values are measured. (Note an ambiguity in the present title; does or does not the "ratios of" apply after the "and"?) >> We have reordered the title, but don't have a better suggestion. 2. Abstract - see general comment. The first sentence says (albeit with an English ambiguity) that we have measured fragmentation probabilities and have measured ratios of br's. Whereas we have measured ratios of br's and used them plus assumptions to derive framentation probs. Later, the word "also", combined with "first reported measurement", implies that we have also measured absolute br's. Whereas we have used the measured ratios of br's plus assumptions to derive these absolute br's. We wonder about the last sentence of the abstract. A look at the conclusion section suggests that all we have done is find "good agreement" with some models. What are the implications? >> Not clear as to the sign of this comment. The abstract has been slightly >> reworded. A more explicit suggestion here would be helpful. The >> emphasis in this paper is the measurement of the >> f_u, etc and BR's, which is why they have received top billing. 3. P 3, before eq (6), "cross section" needs changing. At least say "observed cross section", but that is still unsatisfactory. It would be very strange to say that "our observed pbar-p cross section is 1pb", for example. Maybe state explicitly "cross section times detection efficiency". >> Actually, we agree that the adjective "observed" is required. In fact, >> the concept of "observed cross section" is something some of the authors are >> quite comfortable with. 4. P 3, below eq (6). Here the fragmentations things are first discussed. It is very possible that readers will not understand correctly what these things are. So perhaps a separate paragraph is needed. In particular, it surely needs emphasizing what happens to any Bs** mesons that are produced. Also any relationship with the older "fragmentation functions" that many readers will be familiar with should be mentioned. Finally, the text says "we will refer to these probabilities as fragmentation fractions", but the title and abstract refer to them as fragmentation probabilities! >> We believe that this paragraph does give a reasonably succinct >> definition of these fractions. We explicitly say that we call these >> "probabilities" fragmentation fractions, so we see no confusion in this >> nomenclature. We also explicitly state that these include contributions >> from heavier B hadron states. 5. P 3, para beginning "The fragmentation..". "largely unmeasured" should be replaced. From what follows, it appears that the only measurement is a poor one of fs - then say so. >> Have replaced "largely unmeasured" with "not well known". "if... independent of the flavor and energy..". Is independence of flavor a reasonable assumption? - and of energy? Eq (6) implies that we assume energy independence, but nowhere is this stated - it should be. >> We are making a general statement of an assumption that has frequently >> been made in the literature to interpret different measurements of these >> fractions. "strange meson production in jet fragmentation" could be replaced by " strange meson rates in light quark fragmentation". At least the first ref [11] does not discuss "jets"; and there are b jets. >> Done. We now state "...in quark fragmentation..." because [11] also >> has a measurement from CLEO using charm meson production. "large uncertainties", does this mean large stated error, or large uncertainties in assumptions needed to extract the number? If the former, we could state the result and error, to avoid guessing what is "large"; if the latter, we could state that our extraction has much smaller uncertainties. >> The DELPHI measurement referred to here is based on a number of >> assumptions as well as poor statistics. We don't believe it actually >> is helpful to emphasise it, except to note that it is the only one >> using the b system. Depending on what your prejudices are, you can >> either ignore it and consider other measurements much more precise >> or view it as the ONLY relevant measurement to compare with. ref [13] is inappropriate. We would not go there to find information on fragmentation fractions. >> This is where one can find a coherent summary on B mixing, BR and >> lifetime measurements that illustrate the use of the role of f_s, >> f_d in interpretating these data. If you have a better reference, >> we would gladly use it. Is there no information on the f from LEP expts? If not explicitly given in papers, at least quickly derivable from LEP (plus CLEO) published results? Is it not possible to get f from semi-leptonic decays? >> No, except [12] and possibly the CLEO measurement in [11]. But this would >> not be "quickly derivable" or be very accurate given the poor job on fs. "this fraction" should be "these fractions" (also in the previous para). >> Done. 6. Section II, We think there should be some mention of trigger rates and prescales here. This paper is for PRD so space is not a problem. >> The triggers relevant to this analysis did not have any prescales. >> It is not clear what additional information the trigger rates >> provide without some context regarding the overall limitations of >> of the trigger and DAQ system. They are totally dominated by >> background sources. 7. Sect II. The muon PT requirement is mentioned only for the K+ mode. Was it only used there? And an extra sentence explaining the cut would be helpful - presumably to avoid a region where the acceptance is rapidly varying and has some uncertainty. >> We note that "identical requirements were made on the quality and >> and transverse momenta of the muon candidates,..." at the bottom of >> Pg. 6. The point is not that the efficiency is not well known--it is >> actually very well known from a statistical point of view. The motivation >> for the cut is to ensure that the muons are in a region of reasonably >> high trigger efficiency, which is the statement we make. 8. Sect II. On the K*+ mode. It is disconcerting to read the detailed description of a method to find this signal, and later discover that the result is not used! We learn in Sect III that this method is just one of three methods used, and is not the favored method. At least there should be a comment at the start of the paragraph. Maybe say that we aim to prove that a significant signal is present, and that later (next section) we will use a slightly different method to get our best estimate of the truly K*+ contribution. And at the end of the para conclude that we see a signal, and that the 12.9 is used as a check on our favored method. The same comment applies to the K*0 and phi modes. >> It is not clear to the authors how to incorporate the suggested change >> in wording in Section II without having to basically discuss what >> is contained in Section III. We recommend that Section II stand more >> or less as it is, and append to the end of the first paragraph of Section >> III a statement that explains that we will get a better measurement >> of the rate by taking into account the possible non-resonant contributions. 9. Sect II. The use of fit CL cuts requires and implies that we understand reasonably the errors involved. Are some simple checks possible? For example, for mode JX, would a plot of the mass difference, M(JX) - M(J), give a good check on the signal? >> There have been many checks made, most of which is in the documentation. >> We state clearly in Section IV how we accounted for the efficiencies >> of these requirements (by measuring the loss of signal events in data) >> and verifying that they were insensitive to topology (bottom of Pg 12). 10. Sect II. This Section is long. Perhaps it should be broken up into subsections, (i) general, (ii) on J/psi, (iii) on non-resonant modes, (iv) resonant modes. >> We have broken this into three subsections. 11. Sect III. It is very hard to understand just what was done here. We believe that most or all readers will not understand. Part of the problem is the word "normalised" . It must be told in more detail just how anything was normalised. Overall, the problem is that we have a complicated system. There are 4 contributions, B.K*, B.Kpi, nonB.K*, and nonB.Kpi (where "Kpi means non-K*). As far as one of us could understand what was written, all three methods fit to K* plus background, the assumed background shapes are different in method 1 and method 2, and method 3 is a subset of method 1. It is completely unclear how comparison of the different methods gives information on non-K* contribution. For example, if there was equal B.K* and B.Kpi, what would we expect for Nsb, Nfit, and Nwin ? >> It is not clear what is being requested here. We state that the >> "normalised" B sideband regions have been normalised to the >> "non-B events as determined from the B invariant mass distributions." >> Is this not enough? >> >> If a non-resonant contribution does exist under the K* or phi peak, >> then it would increase the >> rate of events determined by selecting on the K* or phi mass. >> The resulting number of decays would be larger than the >> rate determined by either sideband subtraction using the B sidebands >> (since this selection would include some non-resonant part). >> We have added a statement to this effect at the bottom of Page 10. 12. P 12, middle para. Does the B quark epsilon really come from ref [18], a 1983 paper? >> We have included a more up-to-date reference. (Chrin). 13. P 12, middle para. "The B mesons were decayed using the CLEO B decay model". Does CLEO have a B decay model? All CLEO provides is a table of how to decay B's in each of their decay modes that uses varying theoretical models depending on the decay mode. What's actually selected by CLEO are the parameters to use in each decay model used. In most cases there is only one parameter; namely the branching fraction. This point aside, the only relevant decay modes to evaluate the signal efficiency are the those involving J's. We would not think CLEO has very much to say about their dynamics, and would expect that the "decay model" used might be simply phase space. Certainly CLEO will have absolutely nothing to say about Bs decay, since they don't exist as far as CLEO is concerned. >> The reason for using it is that CLEO puts in the correct helicity >> distributions in the decay. 14. P 13, tracking efficiency paragraph. One of us read this over and over. And concluded that the way the error on the tracking efficiency is estimated is by (i) calculating the efficiency in MC events (ii) calculating it for MC tracks embedded in data events. (iii) taking the difference between these two numbers. If this is indeed all that was done to come up with a tracking efficiency error of 3% then the analysis is incomplete. >> The documentation details the analysis used to estimate the >> tracking efficiencies. A number of techniques were used to estimate >> these efficiencies, including the ones used in previous B papers. >> The authors and godparents did not believe >> these details added any real information to the presentation of the >> analysis. The quoted 3% uncertainty is that associated with only >> the decay-in-flight correction. The uncertainties on track-finding >> and pattern recognition are less and are included in the uncertainties >> on epsilon_meson. Both cases calculate the efficiency for the same object: a MC track, so at best the study probes the effect of the event environment modelling on track reconstruction, but says nothing at all about the other more important component, which is the efficiency for finding a single isolated track, including all applied quality and vertex cuts. It would be good if there were some way to estimate tracking efficiency from the data. Then we could show (hopefully) that the MC simulation is reasonably correct. Restated, is there any evidence that the MC tracking efficiency should be believed? >> We refer back to the documentation for what was done in detail. >> We note that the vertex and vertex-mass constraint efficiencies have >> been determined separate from the pattern recognition efficiency. 15. Sect V. We would prefer a clearer separation here into "measured" and "derived" quantities. The measured results are in Table IV. It is good to see this confrontation with correlated errors. But is it possible to go further? Could we give a Table of correlated errors? We wonder how PDG, for example, would be able to use this Table in a global fit of branching ratios? "..these two sets of measurements are not statistically independent". We should give guidance to a reviewer or PDG or whoever on which set to use. >> We welcome specific suggestions for how to improve the separation >> between measured and derived quantities. We tried to do this in the >> current draft by presenting the measured values first and then deal >> with the derived quantities in separate subsections. >> Specific suggestions on how to further sharpen this line would be >> welcome. >> >> We're not sure how a table of correlated uncertainties would/could >> be used in this case. In the case of PDG, these ratios could be >> used in exactly the way we have used in Section V.A, though they >> may prefer to use other assumptions. >> >> We are not sure what guidance you would have us give the reader >> regarding the results in the PRL. We believe the interested reader >> will make that choice based on what he/she is interested in or focused >> on. 16 .P 15. After Eq (12), "..we use these data to constrain both the fragmentation fractions and the meson br's". Is that true? What follows is (1) assume f values and see what br's we get, (2) assume some br values and see what f values we get. That is, we do not globally constrain anything, and we do not do "both...f and br" but rather just one if we make assumptions about the other. >> This is not quite true. The very first thing we calculate is >> the product fs/fu x BR(B_s -> J/psi phi). In any event, we do not >> imply that we perform a global constraint. The statement is that >> we can use these data to learn more about the f_i's and BR's. 17.P 15. At the start of sub-sect A, it would help to say "In this subsection, we assume that fu=fd, and we assume a value for fs. Then we derive information on absolute br's using our measurements." Because (in part) we later claim to be determining fu and fd and fs. >> We actually make part of that statement (fu=fd) in words at the >> bottom of the paragraph, motivated by the reality that we are using >> world average BR's that have been derived with this assumption. >> The statement about fs is made in the 3rd paragraph at the point >> where it has to be made. Note that the result in equation (14) only >> makes the assumption fu=fd and no assumption about fs. Therefore, it >> would be confusing to make the statement about fs until after that >> result has been presented (which is what is done). 18.P 16. We, and possibly other readers also, would like some assurance that the fs measured in refs [11] are comparable to ours. Are the definitions equivalent, are the contributions from baryon decays and excited states (Bs** etc) similar or small? And, is it appropriate to include ref [12] here since it has "large uncertainties"? Also, we would remove the sentence about ref [25], because refs [11] are all about suppression of strange hadrons, and try to quantify that suppression. >> A reading of the literature very quickly demonstrates that >> it is hard to make any general statements about the fs's (or gamma's) >> that have been measured before, since they have been measured in very >> different contexts. Since there is no hard theory to support either >> a claim that they are all different or all the same, we have chosen >> to be conservative and associate with our "assumed" fs an uncertainty >> that is deliberately large enough to subsume all these. >> We don't believe we should exclude [12] simply because of large >> uncertainties. We refer to [25] because this paper presents an attempt >> to consistently interpret all the data (much of it from refs [11]) from this >> specific point of view. 19. P 16. "We can also use these data to improve our knowledge of the branching fractions...". Before reading this paper, our knowledge of these br's was summarized by PDG, ref [13]. So improving our knowledge means getting br's with smaller errors. But, the errors in eqs (19) - (22) are LARGER than in ref [13]. So, our knowledge is NOT improved. In principle, we could do some work, combine eqs (19) - (22) with ref [13] and get new world averages. But, it seems we can only do that for one of the four modes, because of the correlations. So, how has our knowledge improved? And, how can a reviewer use these eqs (19) - (22) unless told the full correlation matrix involved? >> Our measured ratios are uncorrelated with the PDG BR's. When we >> use our measured ratios and the PDG BR's for the example noted in >> the draft, our resulting BR(B+ ->J/psi K+) is still independent of >> the PDG's BR(B+->J/psi K+). A weighted average of the two can then be >> taken to refine the world average value. A similar situation applies >> for the other three BR's we quote. The resulting set of 4 new BR's all >> would have approximately 30% smaller uncertainties than the current world >> average, and are now, of course, correlated. The correlation matrix >> for these 4 BR's is trivial (though tedious) to calculate. They have >> all the information required for this in Table IV. >> >> To reduce the amibiguity resulting from the first statement, we have >> modified it to read like "We can also use these data to estimate the >> branching fractions...." We consider that many (maybe most) readers will not understand what has actually been done here. To read that we use "the world average values" strongly suggests that we do a global fit. But we dont. It should be stated explicitly, for example, that for the K*+ mode we use world average values for K+, K0 and K*0 but not for K*+. We could have used the K*+ mode. >> We have added a sentence to the bottom of the first paragraph on Pg 17 >> noting that this result is independent of the PDG world average value >> to further clarify this point. The following para (bottom of P 17) begins "We have compared our results...". Many readers will wrongly think we refer to the immediately preceeding results, i.e., eqs (19) - (22). So replace "results" with "branching fraction ratios". >> Done. 20.P 18. We would delete the last sentence of sub-sect A. "The predictions agree well.." is the conclusion. >> Done. 21.P 18. At the start of sub-sect B, it would help to say "In this subsection, we make assumptions about br's . Then we see what our measurements imply for (1) fu/fd and (2) fs if we assume fd = fu." Or similar. The reader must be alerted that this section is not just a continuation of the previous section. >> OK, we've added something like that. 22.P 18-19. Eqs 23 24 27 28, need signs corrected. >> Whew! Done. 23.P 19. We consider that sub-section V.C contributes essentially nothing, and should be deleted. >> The authors and godparents disagree. Having the ratios fs/fu and fs/fd >> allow us for the first time in the same experiment (modulo two assumptions) >> to make estimates of the values of fu, fd and fs. We appreciate that the >> need to assume values for fc and fbaryon, no matter how well justified >> weaken the argument. However, we believe they are on firmer soil than the >> calculated values we currently use even in our own publications. 24.P 21. Sect. VI. We would first say what we have measured. >> We have added a introductory paragraph doing this. Then say what follows from the measurements plus what specific assumptions. >> OK. That is already the case. If eqs (40) - (43) are retained, one or two sentences of explanation must be given. For example, " The branching fraction for any one mode here was obtained using our measured ratios plus the world averages for the other three modes. The fractions given here are correlated." >> We believe this sort of statement is misleading, nor does it provide >> any additional information. Clearly, one has to consider correlations >> if one wishes to use these values. We consider that considerable rewriting is required in this Section. Replace "We have used these data..." with "We have used our measurements, plus the assumptions that fs=fu and fs=(0.4+-0.06)fu, to derive [eq 39]. Here the last error is due to the assumed error in fs. There are no previous reports of a B0s branching fraction to a final state with a J/psi." >> OK, we have done basically that. Remove the sentence "These data are consistent with a B0s..." Or, at least remove the B0s fragmentation part, which does not belong here, since we have just assumed 0.40 ! >> Have done the latter. Remove the sentence "An analysis of the ratios...". We do NOT confirm that any things are equal. >> We have softened this in response to other comments to read "An >> analysis of the ratios of branching fractions supports the ...". Remove the sentence that includes Lambda-b. >> See response to comment 23. Replace the potentially ambiguous fs/(fu,fd) with fs/fu . >> OK. Replace "These measurements imply a" with "Thus our results suggest" . [Where results = measurements plus assumptions, and suggest because we have had to make assumptions.] >> OK. Jeremy Lys, for the LBL group. =========================================================================== MCGILL Comments =========================================================================== Here are the McGill comments to the PRD draft "Ratios of b quark fragmentation probabilities and ..." First of all we should congratulate you for the very nice piece of work you've put together here. We have one major comment/question: -> What is the purpose of quoting absolute branching ratios, using the PDG values as inputs? Our understanding is that by doing so, we do not get values better than the PDG averages. Furthermore the branching ratios we extract this way, are not independent of the PDG values. How should one go on and use these values? We do not think that one can combine these measurements with the previous PDG values, due to this correlation. Why not quote just ratios of branching ratios? Otherwise state as clearly as possible in the paper, how should one interpret the quoted values for the absolute branching ratios. We are a bit confused about this. >> The branching ratios we determine are not claimed to be better than PDG >> estimates and that was not the criteria. Each measurement is independent >> of the measurements of the same value from PDG. However, they depend on >> the PDG branching fractions of the three other decay modes. In practice, >> one can combine these measurements with the latest results from CLEO, which >> are comparable in precision. We will try to emphasise this point in the next >> draft. We also have the following comments/suggestions that could help to further improve the paper. Here they are (negative line numbers indicate that we start counting from the bottom of the page upwards): Page/Line Comment --------- ------- Title How about switching the 1st and the 2nd part of the title, so as to read "Bottom meson branching fractions involving J/\psi mesons and ratios of b quark fragmentation probabilities." since the "involving the J/\psi mesons" refers to the "ratios of...bottom meson branching fractions" >> Godparents were the ones who mandated this ordering (in part to contrast >> this paper from the earlier PRL). Why, by the way, do you prefer this >> order? Abstract/5 Add the word "absolute" so as to read "We also determine the *absolute* branching fractions..." >> We tried this and realised after reading it that the nomenclature >> "absolute" is unusual. We talk about "branching fractions" and >> "ratios of branching fractions". 2/3-4 We think it would read nicer if written as follows: "The lowest-lying bound states are the pseudoscalar mesons (B+, B0, Bs), formed by one bottom anti-quark bound to one of the three lightest quarks (u, d and s respectively)." Also, since we talk about anti-quarks here, it's more appropriate to put lines 21,22 ("We use the convention... decay mode.") somewhere here. >> Yes, we have adopted that structure. We have chosen to keep the >> phrase about charge conjugate modes where it is, though it has been >> rewritten on the suggestion of a collaborator. 3/eq. 6 It's more clear to write "\epsilon^{ J/\psi K^{+} }" since this efficiency includes the J/\psi and the K^{+} efficiencies, and in eq. 7 we split them to write \epsilon{ J/\psi } and \epsilon{ K^{+} } >> The notation we use here is consistent with the notation used later in >> the paper. We believe adding the J/psi to the notation clutters it up >> and potentially increases the confusion of the reader >> (presuming that they have made it that far without getting turned around). 3/5-6 Write "... \sigma(p p-bar --> b-bar) is the *anti*-quark production... the fragmentation of a b*-bar* will result..." >> Yes, fixed. 4/19 Since this is a PRD and footnotes are accepted, it would be more convenient for the reader to have the coordinate system defined at a footnote on this page. Thus, the references will be reserved for real references. Also: add the definition of "r" in the coordinate system description, since we use it later on, and take the hat off the "z" since we do not use the z-hat anywhere in the paper. >> We would prefer to keep it as a reference but have included the definition >> of "r". 4/18-22 Give the \eta coverage of the tracking detectors for completeness. >> We have added the approximate pseudorapidity coverage of the CTC (since >> that is what really matters in this analysis). 4/23 Write "...charged particles with transverse *to the beam* momentum P_{T} > 0.35 GeV/c, ..." so as to state what is the momentum transverse to. >> OK. Have rephrased it to make it read more smoothly. 5/2 State here that these muon chambers having 5-9 interactions lengths of material in front of them cover the |\eta| < 0.7 region. >> Have changed this to $\sim 5$\ since this refers to the CMU implicitly. 5/3 Replace "flux" by "yoke" since the yoke is used as a path for the flux. Also say "... outside the magnet return yoke (an additional 4 interaction lengths of material) in the central...". Since we said how many interaction lengths of material the CMU has in front of it, it's fair to state what the situation for the CMP. >> OK. 5/11 Add the word "track" to read "The first level trigger *track* efficiency rises...", since we guess you mean the single track efficiency here. >> No, that is the overall efficiency for the requirement as a function of >> the highest momentum track (the first level trigger requires the presence >> of two muon track segments). 5/14-15 Scratch "in the axial view" and write "...above a *transverse* momentum of \sim 2.5 GeV/c." >> OK. 5/15 Write "...to match within 15^{o} *in \phi* of the muon candidate." >> OK. 5/18 Rephrase to read "...match with two track segments *in the muon chambers* and that the..." >> OK. Have removed the use of "segments". 5/-6 Explain what do we mean by "high-quality" CTC tracks. There is the space to do so. If you don't want to get into details you can leave this characterization out. >> OK, have struck the adjective. 5/-2 Replace "signs" with "charges". >> OK. 6/9 State that we take all charged tracks (except the J/\psi muons) as K+ candidates by writing something like "For the decay channel B+ --> J/\psi K+, we consider every charged particle with P_{T} > 1.5 GeV/c, as a K+ and require the resulting B+ candidate to have P_{T} > 8.0 GeV/c." (Ooops... somewhere there it should be told that we do not allow the J/\psi muon tracks to be considered the K+ candidates...) >> OK. We think the exclusion of the muon tracks to be self-evident. 6/21 We've already talked about the B-meson secondary vertex, but since we talk about c\tau, we should say something about the primary vertex (the initial point of the flight path). >> OK. We've described how we define the primary interaction vertex. 7/1 Add "and on the" to read clearer: "...momenta of the muon candidates *and on the* constraints on the fits..." >> Not necessary in our opinion and makes the sentence more ponderous than >> it need be. We believe that the parallel structure works. 7/16 Since we quote the J/\psi PDG mass we constrain the muons system to, it's probably fair to quote the Ks mass we constrain the pions to. >> We would rather not. It means rephrasing that whole sentence. 7/19 Scratch "that" and add "to" to read: "larger than 0.1 cm and its transverse momentum *to* be greater than 1.5 GeV/c." >> Good. Done. 8/2 Add the forgotten slash to the J/\psi notation. >> Done. 8/last Scratch the word "symmetric" before the "K*(892) decays" to avoid unnecessary nomenclature. >> Done. 9/first paragraph It would be appropriate to state here what the MC studies indicated for the K* decays where the incorrect kaon and pion mass assignment yield an invariant K\pi mass within the K*0 mass window of \pm 0.08 GeV/c**2. (e.g efficiency relative to the correct K\pi assignment) >> We have now included the details of that lineshape (we agreed from the >> start but forgot to put it in). 10/17-18 Add "B" and "two body: to read: "... using the normalized *B* sideband distributions to model the shape and size of the background under the "two body* resonance signal. The resulting number of *B* events..." >> Good. Done. 11/11 Replace "cancels for" by "is common to" to read: "...decay and is common to all decay modes studied here." >> Done. 12/-5 Spent a few words on how you got the 1% systematic uncertainty. >> Done. 13/8 Add "B" to read: "..lifetimes of the three *B* mesons..." >> Done. 13/10-11 Since the lifetime of the B mesons is a source of systematic uncertainty, include this systematic uncertainty in table III. >> These are given in Table II as part of the uncertainties on epsilon_ctau. 13/15 Spelling: "imbedding" --> "embedding" >> OK (so I can't spell...). 13/17 Use plural: "uncertainty" --> "uncertainties" >> Done. 13/20 Since 60% of the K+/- mesons that decay within the CTC volume (4% to 6%) are not reconstructed correctly, this means that (4% to 6%) x 60% = 2.4% to 3.6% of the total K+/- mesons are not correctly reconstructed. Why is a 3% systematic uncertainty on the \epsilon_{K} conservative then? >> We have struck "conservative" since it serves no purpose. The point, >> however, is that there is only a small uncertainty on the 4-6% of >> kaons that decay. The uncertainty is in the fraction that are properly >> reconstructed in the CTC (the 40%). We correct by this fraction. We >> assume that the uncertainty on this fraction is -40% and + 60% when we >> assign the +-3% uncertainty on this correction. We think CDFSIM does a >> a better job than that, but are not willing to quibble over it. 13/-4 Spelling: "determine" --> "determined" >> Done. 14/7 Replace "perturbing" by "changing" to read: "...This was measured by *changing* the renormalization scale..." >> OK. 14/-8 "...we assumed that the relative..." Is there any reference to justify this assumption? >> Yes, there are some relatively recent LEP results that we now reference. 15/3 Replace "were" by "was" to read: "The observed number of signal events, listed in Table II, *was* corrected by..." >> We have made it consistently plural, since we are referring to all the >> relevant numbers in the table. 16/-5 "We use these data to improve our knowledge of the branching fractions..." See our major question; how is the reader supposed to combine this information with the old ones? Are these values better than the PDG average? >> No, they are however competitive and could be combined with the PDG >> values. 17/-6 & 18/3 Use a consistent spelling for "factorisation" >> We've now tried to do so. 20/3 Add a comma after "This" to read: "This, combined with our..." >> Done. 20/7 Spelling: n\"{a}ive --> na\"{\i}ve >> Done. 21/-1 Add the word "current" to read: "in conjunction with the *current* world average..." >> OK. 30/fig.5 How about using open squares and solid circles, or the other way around, in order to distinguish them better when they start to overlap? >> We've tried this. Will see if we can come up with a better presentation. >> No promises however.... 33/table caption We guess it should read: "The ratio of fragmentation *times* branching fractions for the..." >> Done. That's all guys. Again, very good work, complete and solid presentation. Congratulations to the authors and all involved. Kostas Kordas (for the McGill write-up) Additional Comments from Klaus Strahl ------------------------------------- Here are some more comments to the b fragmentation paper. Some of you have seen those already in some private communication. I have not been part of the official discussion, thats why they are not included in the "McGill" set. They are mine, and only mine. So: Shoot the messenger not the group....... I've only left those that I deem fairly important, and they are only those, that are NOT included in the McGill set: Page / Line Comment ----------------------------------------------------------------------- *** 8 / 6 The K^{*+} signal in Figure 3c does not contain 1800 events. There are a few hundred at best. >> Well, just doing a quick count ourselves easily puts us over a >> a thousand. The issue here is that we estimate the rate by performing >> a fit using a BW lineshape that has a reasonable amount of cross section >> in the region beyond one full-width, which isn't so apparent in the plot. >> In reality, if we really want to measure the K* rate, we should do a more >> complete job putting in a more correct relativistic form for the K* >> lineshape. It is simply not worth it in our opinion. The number quoted >> (1800+500) is the result from the fit. After consultation with the >> godparents, we have dropped the statement just to make everyone happy. ** General You don't talk about reflections between the different channels. Especially J/\Psi \Phi and J/\Psi K^{*0} ought to crosstalk and maybe J/\Psi K^{*0}, J/\Psi K^0 and J/\Psi K^+ as well. I am sure you studied that, so please mention it in the paper. >> No, there are no expected reflections between the different channels. >> In particular, the phi being right on threshold has no possibility >> of reflecting into the K* mass region or vice-versa. We believe the >> B mass plots support this quite clearly without having to belabour >> the point. However, we now make the statement you requested at >> the end of the second on Non-resonant decays. * 13 / 16 There are several issues in the K^ decays in flight: I don't understand why 3% is a conservative estimate: Taking the bounds that you give: 4%*(1-40%) =3D 2.4% and 6%*(1-60%) =3D 3.6% Your 3% is right smack in the middle of that. Why is that conservative? And moreover: If we know both the reconstruction efficiency for decaying k's and the fraction of K's decaying, we should correct for that effect. That shifts the numbers systematically in a known direction and is not adequately described by a symmetric systematic error. It also reduces the systematic error....[a little bit]. >> See our comment above. * 15 / 4 If you correct the number of observed events by a "relative detection efficiency" you are not getting a "production cross section time BR". It is that times an arbitrary factor and times the fragmentation fraction. >> We have struck the phrase "...to yield a production cross section times >> branching ratio for each channel." just to avoid this ambiguity. I promise to behave now for a while..... (well, for a short while anyway). This should be it. Klaus Strahl =========================================================================== Randy Hans' Comments =========================================================================== Hi George and Pekka. I read CDF 3609 and have a few minor comments. I must apologize. I have not had time to read all of the background material, but I don't really see anything wrong in the analysis, and I'm sure that the authors, godparents and the B group have worked hard to insure that the analysis is correct. My comments are mostly on language and presentation of the results. Here goes: Page 2, first paragraph. Your first two sentences imply (to me) that the lowest-lying bound states involving heavy quarks (bound to a light quark) are the B+, B0 and Bs. It is my understanding that generally, the phrase, Heavy Quarks, implies the c, b, and t. Consequently, the D mesons would be the ones that fit your description. Also, I wouldn't have said that you were studying QCD (since that, to me, implies that you are studying perturbative QCD). I'm not sure how I would reword it, but you might think about it. (Non-perturbative QCD bound states, or some such.) >> I consider QCD (and I think most people do) to refer to both the short >> and long-range features. We agree with the reference about "heavy >> quarks"-- that has been replaced by "bottom quarks" in the first >> sentence. Also, the last sentence in that paragraph, "...yield insights into the complex interactions that take place between a quark and anti-quark pair at short distance scales." This doesn't really say anything, and sounds to me like you are trying to sell me a load of manure. You don't need to do that. You have made a nice measurement, you don't need to dress it up. I'd reword this as well, and make it less vague, or just pick something specific you want to talk about. Now those comments are definitely just my opinion, and other people will probably disagree with my style. Take 'em for what they are worth. >> To the extent this is a motivational statement, we prefer to keep it there. >> However, we have toned it down a little by removing "complex" (which may >> be what you are reacting to...). Paragraph 2, 7th line. I don't like the use of the word unique. Most decay topologies are unique. This is not what you mean. You mean that they are triggerable by CDF, but that is clunky, so how about "...hadronic final states that have distinctive final state topologies relative to generic QCD interactions". Or something like that. >> OK, have replaced "unique" with "distinctive". 9th line: "The data come from a 19.6 pb-1 run ..." This sentence sounds a little odd to me. Why don't you use a more standard version of this, something like, 'The data set consists of 19.6pb-1 of 1.8 TeV proton-antiproton collisions produced by the Fermilab Tevatron Collider.' >> We could have been really old-fashioned and called it a "19.6 pb-1 >> exposure". Have taken your suggestion... Last sentence in this paragraph. This sentence sounds awkward to me. How about something like, 'Throughout this paper references to a specific decay mode imply the charge conjugate mode as well.' >> OK. Page 3, 2nd paragraph, 4th line: "Only one measurement of fs..." The 'this' in this sentence doesn't sound correct, shouldn't it be an 'it'? >> We believe the meaning is clear either way. We've changed it to "it". Next sentence. This sounds to me like you are making this issue out to be dramatic, when it isn't. The assumption that fu and fd are the same is reasonable, but should be tested. So you're testing it. Don't try to make it sound dramatic, just give the facts. Like I said, you have a nice measurement, you don't have to try to make it dramatic. >> We don't detect any sense of drama in the statement, except to point >> out that these are important parameters in many measurements. We >> believe that most people don't even recognise this point so emphasising >> it here makes sense to us. Page 5, second paragraph, first sentence. J/psi final states -> state (I think. The trigger just looks for the J/psi final state; it doesn't select the various B decays to final states with J/psi). >> Right. Fixed. Same paragraph, 10th line. segment is not defined (in muon track segment), and in fact, you don't need the word segment at all. This is a CDFism. It is simply a muon track. Same comment with respect to the word 'stub' in the next paragraph, line 4. Also, that sentence seems a little awkward, see if you can reword it to make it a little smoother. >> Right. Fixed. Page 6, first paragraph, 4th line: Shouldn't you have more background in opposite sign dimuons than in same sign, coming from Drell-Yan, c\bar{c} and b\bar{b} events? Ok, maybe the difference is small... >> Empirically, the same-charge spectrum does a good job of describing >> the background under the J/psi peak. It is not salient to the analysis >> but shows that most of the background appears to be due to fakes... Page 12, second paragraph, 8th line: "proton stucture functions", although this is an accurate description, isn't this generally referred to as a 'parton distribution function'? >> Yes. Fixed. 3rd paragraph, 5th line: The 1% number seems unsupported. You said there was no effect. Why 1%, why not 0.1%, or less? You don't give any indication that the 1% came from anywhere, unlike your other systematics. >> We have now stated that this number is estimated by comparing the loss >> of signal events in the different decay topologies. Page 14, first full paragraph, line 11: Why +-0.10 instead of +-0.07? I suppose it doesn't matter. >> It was what was used. Page 18, 2nd paragraph, last sentence: I don't like this sentence. If you want to say that this theory agrees with our data, fine, but we shouldn't be telling the theorists that this is the right theoretical approach. They can decide that for themselves. >> Yes, we agree that one should not get too enthusiastic. We have struck >> this sentence. Page 22, 3rd paragraph, first sentence: "confirms" is too strong. Your measurement has a 20% error. Your result is consistent with the widely-held assumption, it doesn't confirm it. >> We have replaced "confirms" with "supports". Figure 2: The 5 MeV bins seem too small to me, especially in the modes where you don't have that many events. If you widths are typically 12-15 MeV, shouldn't you be using 8-10 MeV bins? >> There are a number of ways of determining the "appropriate" bin-width. >> We first note that the minimum mass uncertainty is less than 10 MeV. >> Since this is what sets the structure in the plots, the bin-width should >> be chosen small enough not to obscure possible variations in shape in the >> highest statistics channels. On the other hand, the number of events per >> bin plays some role in terms of presentation. We feel that the choice >> of 5 MeV is a reasonable compromise between these somewhat competing >> pressures. All in all, it looks like a good job. I look forward to it being out so I can show it to my CLEO colleagues. Randy =========================================================================== TORONTO Comments =========================================================================== We, the Toronto group, reviewed the PRD draft entitled "Ratios of b Quark Fragmentation Probabilities and Bottom Meson Branching Fractions Involving J/psi Mesons". Here are our comments. *Title: "J" of J/psi should be italicized. >> OK. *Abstract: "b" of "b quark" should be italicized. >> OK. In text the integrated luminosity is quoted as 19.6 pb^{-1}. >> OK. We quote it as 19.6 in the abstract now. "This is the first reported measurement of this $B^{0}_{S}$ branching fraction." It would read better if we write "This $B^{0}_{S}$ branching fraction is the first reported measurement." >> OK. Put "PACS Numbers:" before PACS numbers. >> OK. *General comments on text. Both "bottom" and "B" are used to represent "bottom". We suggest you stick with one of them through out the paper. >> Have tried to do that now. Since we are trying to publish this on an American journal, it would be better to use American English rather that British English, such as hadronization instead of hadronisation, etc. Or at least try to be consistent. >> Alright. We have removed all the Queen's english. The speed of light symbol "c" should be italicized. >> OK. *Page 2: Line 2: "Quantum Chromodynamics" need not be capitalized. >> OK. Line 4: To be consistent with the rest of the text, remove a comma between $B^0$ and "and". >> OK. Line 13: proton-antiproton -> p{\bar p} Same for on line 18. >> OK. Line 21: "We use the convention that the charge-conjugate state is implied whenever..." It would read better if we write it as "...state is also implied." >> Have replaced this with text suggested by Randy Hans. *Page 3: line 10: Put $\epsilon^{K^+}$ after the description of $\sigma$. It would be better have the definition of symbols in equation six in the order of appearance from left to right. So we suggest the definition of $\epsilon^{K^+}$ be moved to the last of the sentence. >> OK. line 1-2 from the bottom: "The efficiency of detecting the final state $\epsilon ^{K^+}$, depends on an understanding..." It would read better if we write it as "The efficiency $\epsilon ^{K^+}$ depends on an understanding..." >> OK. *Page 4: Line 8: To be consistent with the rest of the text, put signs on the symbols of charged particles. >> Here, we have two K pi charge modes. In this context, we have >> consistently used this notation... Line 14: "It surrounds the p{\bar p} interaction point..." p{\bar p} is redundant as it was mentioned in the previous sentence. >> OK. *Page 5: Line 2: "... the interaction point by 5-9 interaction lengths of material." It would read better as "the interaction point by between 5 and 9..." >> OK. Has been changed to approximately 5 (the 9 was in my dreams...). Line 3: "An additional 4 layers of chambers is"-> "Additional 4 layers of chambers are" >> OK. Line 5: "An additional set of chambers are..."-> "An additional set of chambers is..." >> OK. Line 19: "Approximately $2.06 \times 10^{5}$ dimuon events passed ..."-> "There are $2.06 \times 10^{5}$ dimuon events ..." >> OK. Line 21-25: The sentence is too long. >> OK. Broken into two sentences. Line 26: "... to have opposite signs." -> "... to have opposite sign charges." >> OK. *Page 6: Line 4: "... using same-sign muon candidate pairs." -> "... using same sign charge muon candidate pairs." >> OK. Line 4-6: The sentence "We performed an additional fit ... mass of 3.09688 GeV/c^2." appears to describe "vertex-plus-mass constraint" mentioned later on in the text but not defined. This would be a good place to define it parenthetically. >> OK. Line 21: Isn't the proper decay length positive by definition? If we were to use $c\tau$ as it is used in the paper, it should be explained what "our" meaning of it is or be given "our" definition of it. >> OK, we will define it. *Page 7: Line 12-17: Was the pointing done in 2D or 3D? It's not clear in the text. >> 3D pointing was used. That was why it was not qualified in the text. Line 17: The proper length is already defined on the previous page. >> OK. *Page 8: Line 24: "the two-track system" Why not state it explicitly as "the $K^+\pi^-$ system"? >> Done. *Page 10: Line 2: "We use a Monte Carlo calculation to determine..." Since this is the first time a Monte Carlo calculation is mentioned and there is no references for it, we suggest you add something like "described in Section IV". >> Done. Line 19-20: "... within 0.01 GeV/c^2 of the world average {\phi} mass (1.0194 GeV/c^2)" The significant figures are inconsistent. >> Have increased the significant figures to 0.010. Line 24-27: To be consistent with the rest of the text, put signs on the symbols of charged particles. >> We were being economical by not stating the signs (so K pi refers >> to both charge modes). *Page 11 Line 1 and 4: To be consistent with the rest of the text, put signs on the symbols of charged particles. >> See previous comment. Line 19 and 23: The superscript "(i)" of ${\epsilon}^{(i)}_{whatever}$ is not defined. There are two more instances in the next page and one in page 13. >> Removed. Left by accident. *Page 12: Line 16-18: "The Monte Carlo events were then processed with the same algorithms used to reconstruct the collider data. We then used these data to estimate ..." The term "collider data" sounds awkward. We can avoid using the term "collider data" by rephrasing the sentences as "...used to reconstruct the data. We then used reconstructed Monte Carlo data to estimate..." >> Done. Line 20-21: What's the difference between "vertex and mass constrained fits" and "vertex-plus-mass constraint"? >> None. We have adopted a uniform nomenclature now calling the vertex + mass >> constrained fit "the vertex-plus-mass constraint". *Page 13: Line 2 and 20: "conservatively" is a qualitative term. Remove it. >> Done. Line 8-9: "using vertex detector resolution observed" It not only involves the resolution of vertex detector but the resolution of other tracking detectors. Thus, we propose it to be written as "using tracking detector resolution observed" >> Done. *Page 14: Line 7: We think "perturbing" is not the right word to use in this case. Either "varying" or "changing" would be better. >> Done. Line 10: "varies from 1-5%" ->"varies from 1 to 5%" >> Done. Line 24: There seems to be a space between "1" and "0" of total angular momentum notation. >> Have replaced it with just "psuedoscalar". Line 25: "varied from 1% to 4%"->"varied from 1 to 4%" >> Done. *Page 15: Line 3: "The observed number"->"The observed numbers" >> Done. Line 11: "Note that these two sets of measurements are not statistically independent." It is not clear what "these two sets of measurements" refers to. It would be better if we write it as "Note that these two sets of measurements of the three branching ratios are not statistically independent." >> Reworded to clarify this. *Page 16: Equation 17: "and" is not needed. >> OK. *Page 17: Equations 19-21: Add commas after equations. >> Done. Line 16: "the CLEO dataset" ->"the CLEO data sample" >> OK. Line 23: "D-decays"->"D meson decays" >> OK. *Page 18: Line 3: "non-leptonic"->"nonleptonic" >> OK. *Page 19: Equation 25: >From this equation and on, two uncertainties in the equations are not quoted as statistical and systematic. Right after equation 22, put something like "Henceforth the the first and the second uncertainties in the branching fractions are the statistical and systematic uncertainties, respectively." >> OK. *Page 20: Line 9: Shouldn't the umlaut in "naive" be placed over "i" rather than "a"? Or we could do without an umlaut. >> Beat us some more over that stupidity. It is fixed. Line 15-18: This sentence has nothing to do with the measurements presented in this paper. We suggest it be removed. >> There is some difference of opinion on this statement. Check the next >> draft and see what you still think. Line 20: Is there any reference for the assumption of f_c<<1? >> No. We haven't identified a good one. *Page 21: Equation 38: What happened to equation 38? >> Mistake. An extra line. Equation 39: This and equation 15 are the exactly the same. >> Yes, we will remove the label. Equations 40-42: Add commas after the equations. >> OK. *Page 22: Line 16-19: "A data sample approximately four times larger than the one used in this study is under preparation" It gives an impression that a data sample is being tweaked for the study that uses the same method. It would read better if we write "A data sample approximately four times larger than the one used here is under study." Or we could remove the whole paragraph since it does not have have anything to do with the results presented here. >> Have reworded it as suggested. References [2] Put a line break after the semi colon. >> OK. [11] For two Phys. Lett. references, "B" should be bold and there shouldn't be a space between "B" and the volume number. Also, the volume numbers do not quite look right. How is it possible that volume came out later in time has a lower volume number? >> It was a mistake. Now fixed. [14] "-" is omitted from the definition of ${\eta}$ >> OK. [15] Put a semi colon and a line break after each references. >> OK. [21] "Computer Physics Commun." The right abbreviation should be "Comput. Phys. Commun." >> OK. [22] Remove "CLEO B paper" >> Done. =========================================================================== YALE Comments =========================================================================== George, I realize that these are late but they may still be of some use as we converge for a final form: Overall, a splendid job ... well presented and written and proofread. I only have a few minor points to raise about clarity: page 5: The two muon candidates were required to have opposite charges {rather than 'signs'}. >> Done. page 6: re: the 1.8 and 2.5 GeV/c cuts: the sent. "This ensured that the muon candidates were likely to pass the dimuon trigger requirements." includes some implied meaning ... do you want to let the reader know if you actually required the trigger path to be satisified and/or if you were trying to avoid a trigger turnon threshold? >> Here, we are just stating that the muons are in a region where the >> efficiency of the trigger is relatively high. In the past, a cut of >> this sort has had various justifications (threshold is better measured, >> etc.) but we believe the reason one would want to make such a cut is >> the one we give. In fact, we did not require a trigger cut beyond that >> imposed in L3 to get the events into the dimuon J/psi dataset. page 8: the form 'Fig. 3d)' with an unclosed parenthesis is apparently considered the correct form ... I think it should not be so ... this from is used throughout >> You're correct. These have been changed to 3(d), etc. page 9: 4th line: parameterized ? >> OK. page 10: section III; maybe I'm just slow, but I've tried reading through this section twice now and still get lost (even using Table I). Perhaps I should just try again, and at least identify where I get lost; in the meantime if someone else is puzzled, you may wish to revisit the section. >> OK, we have tried to be more explicit in the intro to this section to >> help guide the reader. Would appreciate any concrete suggestions. normalize? >> The British spelling has been vetoed. page 18, third line: factorization and at the end of that paragraph: polarization >> Ditto. page 19, next to last line : hadronization (see beginning of previous paragraph). >> Ditto. page 19 and 20: the idea here as I understand it is that, in some sense, f_lambda_b measures the fragmentation to bottom baryon states in as much as one expects all such states to lead to lambda_b's by decay ... I just wnat to make sure that I (and other readers) understand the assumption behind the validity of equ. 34; is f_b_baryon = 0.14 ruled out? does it matter? >> Yes, we state that assumption in the introductory paragraph. We have >> stated that assumption more explicitly in the calculation. page 18, line 7: criticize >> Queen's english abolished. page 21: it would be good if you would express your result after equ. 37 and 38 in a form to be compared directly with that given in 32, no? >> Are you suggesting that we put the results in displayed equation form? >> Or quote the ratio? The latter gives no new information because Eq 32 >> is used to determine the absolute fragmentation fractions. If you could >> clarify this, that would be appreciated. At the moment, we haven't change >> this. ... well again I hope this is of some help.