From mont@d0sgim.fnal.gov Fri Nov 13 09:52:23 1998 Date: Mon, 26 Oct 1998 12:37:43 CST From: Hugh Montgomery To: evans@nevisl.nevis.columbia.edu, heintz@BU.EDU, hobbs@sbhep.physics.SUNYSB.EDU, wahl@fsheb2 Cc: mont%fnal.gov.Christenson@fnal.gov, tuts@fnal.gov, pgrannis@fnal.gov, weerts@fnald0.fnal.gov, blazey@fnal.gov Subject: PAC Resent-Date: Mon, 26 Oct 1998 13:39:33 -0500 (EST) Resent-From: wahl@FSHEB1 Resent-To: wahl Dear STT people, Following Uli's STT presentation on Friday we got a couple of questions. o What are the specific gains for some example processes? Uli responded on Saturday with an example of the improvement on the top mass as a result of the increased Z--> bbbar and the concomittant determination of the b jet energy scale. o What is the funding plan? Harry and I delivered the latter to the sub-committee ( Richie Patterson(chair), Marty Breidenbach, Ken Lane). We were fairly frank, indicating that we at present saw the need for money from the Lab/DoE to complete the story. On saturday, Harry did not repeat but did exort them to give us Stage I approval so as to permit us to seek funding. This morning I was summoned by Ken and received a verbal report of what the PAC left them with, it is not yet encased in a ltter from the lab which can, of course, apply further spin. Nevertheless what follows is approximately what the PAC said. I do not feel that I can post it so, please Do Not put it on any WEB site or whatever and add this request to whomever you send it to. ( I assume that Horst will forward to Meena, Ferderic and others working on the STT.) Approx PAC words: "" the D0 L2STT would trigger on detached vertices thereby extending D0's reach for high p_T physics. They showed for example that the trigger can improve the top mass determination using Z--> bbbar . It might benefit other processes. The L2STT is very interesting. The Committee encourages more complete studies. These studies should include the the impact on b jet resolution that a large sample of Z--> bbbar would provide .... and the increase in signal to background ratio of a few important processes. The committee encourages the Collaboratiuon to develop this proposal aggressively. The Committee notes that the Lab. funds for new projects are very limited and that the availability of unused contingency is very unlikely and urges the Collaboration to seek outside funds. "" [ For those not around last week, we have taken a few increases in cost estimates for various items over the last few weeks, some of which were processed as change orders last week. Mike characterised the remaining contingency as 17% of Costs to go and 33% of obligations to go. The gradient over the last few weeks does not give us much of a platform at the moment.] My view of the PAC reaction to the proposal is that despite the vibes that some people picked up on Saturday, the STT group has done rather well here. In more general terms Ken said that he thought the PAC had understood that in general this is a good thing but they would like to get us to jump through the hoop of providing/simulating specifics. One should note that there are zero technical questions about the operation of the trigger. There were also no questions about fitting stuff into the overall trigger bandwidth which is what we often worry about. With respect to developing a response, they are clearly endorsing the t mass example that was presented pn Saturday as a prototype example for what they would like to see. It may be that they missed particular examples in the Proposal. (There is never a guarantee that they have read it.) I sense that they would like us to use simulation rather than back of the envelope stuff, on the other hand our experience in the past is that they tend to exagerate what they need on their first shot. Over the next week we should try and digest this and try and come up with a plan of action. It is also clear that we need to see what we can do about putting some funding plan together. That may be more difficult. Well Done, Mont From heintz@bu.edu Fri Nov 13 09:52:39 1998 Date: Fri, 30 Oct 1998 14:41:17 -0500 From: Ulrich Heintz To: heintz@bu.edu, Harold Evans , Horst Wahl , John Hobbs , Meenakshi Narain Cc: Harry Weerts , Hugh Montgomery Subject: STT plans Resent-Date: Fri, 30 Oct 1998 14:32:45 -0500 (EST) Resent-From: wahl@FSHEB1 Resent-To: wahl Hi everybody, I am slowly recovering from the PAC meeting and our DoE site visit double-wammy. Let me summarize my impressions from both ( I would like to ask you to treat this message as confidential and not forward it any further): * PAC meeting: The questions we received from the PAC in the evening after the presentation were: o The STT would increase D0's sensitivity to certain physics processes. Quantify this increase for the processes that you see as most important. o Where will D0 find $1.9M? I believe that the official PAC report will be encouraging and ask us to keep pursuing the proposal, but in order to get Stage I approval, the PAC will want to see more simulations, showing explicitly what the physics gains are. It is my impression that what the PAC would like to see is really not more details but a bottom line: how much will our top mass precision improve, how much less luminosity will we need to see a 100 GeV Higgs, and the like (these are my choices of topics, not the PAC's). I tried to crudely answer the first one in our answer session on Oct 24 (see http://physics.bu.edu/~heintz/answer.ps for a summary). Frank Meritt's comment was that what I showed was very good. But we'll need more to convince the PAC. There is a significant contingent of e+e-/b-physics people on the PAC and apparently their reaction first was rather negative, largely because they didn't get the point (a question that I was asked by Jeff Richman: "how many b's would you get on tape with or without the L2STT" shows that). Other members of the PAC were more favorable and they did influence the general thrust of the PAC reaction. But this underlines the point: we must present a crisp (and therefore simple) bottom line at the January PAC. If we do that - it is my impression - we will get approved. There also is significant skepticism within the PAC (led by Keith Ellis) about the use of the WH->qqbb channel. We must be very careful about this one. If we can convince the PAC that the L2STT will help us find the Higgs - that may be all that is needed as a bottom line. Everybody will understand this. However, what I am worried about is: if we try to make that case but are not convincing, we may be toast no matter how good our case may be otherwise. So, some solid studies with unambigouos results are needed (hint, hint, John). Lastly, the comment was made that this would be a much easier deal if it cost as little as CDF's layer 00 (500k$ with most of it already promised from foreign sources). We may want to think about staging the trigger to first build the r-phi part and then the z trigger. We also have to develop a funding plan that outlines more clearly how much money we are really asking for in case of the engineering. I know the cost of the engineering at BU will be less than estimated. The same seems to be true for Stony Brook. We need figures from Columbia and we need to decide what's done where (especially with regard to Saclay) to nail this down. * DoE visit: PK Williams and Jeff Mandula were at BU the last two days. I presented our plans for the L2STT to them (largely a compressed version of the PAC talk). Afterwards, Meenakshi and I also had the opportunity to discuss it with PK. Notably - and much like at the PAC - there were no technical questions asked. PK's overall reaction. I think, was positive. The word that he also clearly picked up was "Higgs". He indicated that he didn't care whether we can get a few more or less Zs - again this is a more complicated argument. So here again what's needed is a crisp bottom line. "What is the compelling argument for this trigger?" is what he asked. If we can make the Higgs case, that would do it. But again, it has to be compelling. When asked how we should approach DoE for funding his answers were rather oracle-like. He thinks Fermilab should have the funds to do this. It is clear that he is not happy with Fermilab spending DoE/HEP money on the Sloan Sky Survey. On the other hand, he seemed unhappy that we asked NSF for money for it. His words were approximately "I don't know what they [the lab] want to do. It seems they want to give this [the L2STT] to NSF." He seemed to see it as a plus that there were several young faculty on this project; that this was an opportunity (for DoE?) to boost their careers. In response to the direct question whether we should submit a supplemental funding request or how we should propose this to DoE, his answer was that we should do whatever we want to do. Meenakshi and I read the oracle as saying we should submit a proposal to DoE, probably best jointly. After all, we never really approached DoE about funding when we proposed the MRI to NSF. I was told, by the way, that the MRI announcement will probably come out next week and that the deadline probably will be similar to last year (ie in January 99). Time to get working on it, therefore. Conclusion: For the PAC (and NSF and DoE as well), we need to prepare a watertight physics case. We have to answer (and support with simulations) the following questions. The simulations do not have to be full-blown GEANT - I am sure they will be happy with parametrized MC and scaling from Run I. 1. what is the integrated luminosity to see a 100 GeV (for example) Higgs with and without the L2STT? Improvements from all-jets mode and Z->bb signal. 2. what is the precision with which we can measure the top mass (w/ and w/o L2STT)? Improvements will come from energy scale (Z->bb) and mass measurement in all-jets mode. 3. what is the precision with which we can measure the top decay branching fractions (w/ and w/o L2STT)? Improvement due to less biased and larger all-jets sample. 4. what is the significance with which we can see and the precision with which we can measure single top production (w/ and w/o L2STT)? Improvement from ability to trigger on all-jets mode. 5. What other hadronic modes are there that contain b quarks in SUSY or other models, that the L2STT would make us sensitive to? 6. How much does the track pT threshold sharpen up, by how much can we thus raise the threshold at Level-2 and by how much is that going to decrease the overall rate? 7. What is a likely trigger scenario with all the L2STT advantages built in and what are the improvements wrt the scenario w/o L2STT? This includes overall rate reductions and therefore looser trigger requirements even for channels that do not use the L2STT. Based on these numbers we can then formulate a reply to the PAC (which will not necessarily contain all these items - remember it has to be simple and compelling) Please send me your comments, Ulrich [Part 2, Text/HTML 140 lines] [Unable to print this part] From wahl@sg1.hep.fsu.edu Fri Nov 13 09:53:06 1998 Date: Tue, 3 Nov 1998 13:25:13 -0500 (EST) From: "Horst D. Wahl" To: Ulrich Heintz Cc: Harold Evans , John Hobbs , Meenakshi Narain Subject: Re: STT plans Hello Ulrich, Thanks you for providing us with your summary of your readings from the PAC and your discussions with PK Williams. Your list of physics questions to study is impressively long. I am not sure we can mobilize enough manpower to get all of these things done before Christmas. I think we can get Dan Karmgard and Brian Connolly to work on some of the questions. In particular, the pt trigger onset and influence on trigger rate is something they could do. I am trying to recruit additional help from FSU. Have any volunteers come forward for any of the studies? I sympathize with your desire for "privacy", but in order to get additional help, we have to open up a little bit. About staging: I agree that it would be helpful to have a staging scheme, and what you suggest, namely delaying the z_vertex finder, is really the only possibility since this is the only part that can be separated out. I am a bit confused about your quoting PK Williams as not wanting to give it to NSF. Does this mean that submitting a proposal to NSF-MRI would jeopardize our hope for funding from DOE? I suggest that we use the next STT meeting on Friday to discuss the physics question, to come to a consensus which of the topics we should pursue with highest priority. Given the scarce participation in STT meetings recently, I do not think we have to worry about breach of secrecy. If any of you cannot be at the meeting, please let me know so I can request video-links. Regards, Horst From heintz@bu.edu Fri Nov 13 09:53:22 1998 Date: Tue, 03 Nov 1998 14:06:47 -0500 From: Ulrich Heintz To: "Horst D. Wahl" Cc: Harold Evans , John Hobbs , Meenakshi Narain Subject: Re: STT plans Hi Horst, my request not to forward was meant to apply to my interpretations of the PAC and DoE visits. I don't want that to be spread too widely. It was of course not meant to apply to the plan of work to do. I know the list is long and maybe we have to prioritize. My take is: the most important is the Higgs, next all other specific physics topics, like top mass, single top etc, last the pT turnon . I suggest that John takes care of the Higgs (he is doing that anyway for the SUSY/Higgs workshop I think (?)). I can pursue the top mass precision question further. Maybe Hal can look at the single top. For the turn-on curve, we have to manipulate the trigger simulator to use the STT pT rather than the CFT pT at level2. Maybe Dan and Brian can do that. These studies don't have to be too detailed. As far as interpreting PK goes your guess is as good as mine. I was just trying to convey the spirit of some of the conversation. I don't know the answer - I don't see why an MRI proposal should affect our chances of getting money from DoE? I suggest we pursue both alternatives. Ulrich From meena@d0sgim.fnal.gov Fri Nov 13 09:53:55 1998 Date: Tue, 03 Nov 1998 13:04:20 CST From: Meenakshi Narain To: heintz@BU.EDU Cc: "Horst D. Wahl" , Harold Evans , John Hobbs , Meenakshi Narain , meena@d0sgim.fnal.gov Subject: Re: STT plans Hi, Since I have the trigger simulator setup from Jerry with the current D0 list I can try to change the CFTpt to the STTpt and look at the improvements in rates. This should be trivial to do. I can take a quick look at this for the next STT meeting this Friday. Can we get Harrison involved with assessing the improvemnts for alljets cross section/mass etc. I see his name on many alljets d0notes and your mailing list. Maybe he can do some simple estimates for us? Regards, Meenakshi +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Meenakshi Narain voice:(630)-840-8238 M.S. 357, DAB 6th Floor, fax: (630)-840-8481 PO Box 500, e-mail: meena@fnal.gov Fermilab, Batavia, Il, 60510 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Hi Horst, > > my request not to forward was meant to apply to my interpretations of > the PAC and DoE visits. I don't want that to be spread too widely. It was of > course not meant to apply to the plan of work to do. I know the list is long > and maybe we have to prioritize. > > My take is: the most important is the Higgs, next all other specific > physics topics, like top mass, single top etc, last the pT turnon . > I suggest that John takes care of the Higgs (he is doing that anyway for the > SUSY/Higgs workshop I think (?)). I can pursue the top mass precision > question further. Maybe Hal can look at the single top. For the turn-on > curve, we have to manipulate the trigger simulator to use the STT pT rather > than the CFT pT at level2. Maybe Dan and Brian can do that. These studies > don't have to be too detailed. > > As far as interpreting PK goes your guess is as good as mine. I was just > trying to convey the spirit of some of the conversation. I don't know the > answer - I don't see why an MRI proposal should affect our chances of > getting money from DoE? I suggest we pursue both alternatives. > > Ulrich > > From evans@nevis1.nevis.columbia.edu Fri Nov 13 09:54:12 1998 Date: Tue, 3 Nov 1998 14:11:53 -0500 From: Hal Evans To: Ulrich Heintz Cc: "Horst D. Wahl" , Harold Evans , John Hobbs , Meenakshi Narain Subject: Re: STT plans Hi Uli, Your plan looks good to me. I'll start having a look at single top production. Another thing that comes to mind is the SUGRA 4-b signature. I know that Doug Norman looked into this and concluded that it wasn't helped by STT - but I think that his study wasn't as complete as John's WH-->qqbb in terms of background rejection vs. efficiency. I'll try to look into this also, but probably won't have time to do the in-depth study necessary before Christmas. However, it might be possible to tack this onto the Higgs work and get some kind of ideas.... Cheers - Hal ^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v | Hal Evans | | evans@nevis1.columbia.edu | | Physics Dept. Nevis Labs | | Columbia University PO Box 137 | | 550 W 120th Mailcode 5215 136 S Broadway | | New York, NY 10027 Irvington, NY 10533 | | Tel: (212)854-3334 (914)591-2815 | | Fax: (212)854-3379 (914)591-8120 | v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^ On Tue, 3 Nov 1998, Ulrich Heintz wrote: > Hi Horst, > > my request not to forward was meant to apply to my interpretations of > the PAC and DoE visits. I don't want that to be spread too widely. It was of > course not meant to apply to the plan of work to do. I know the list is long > and maybe we have to prioritize. > > My take is: the most important is the Higgs, next all other specific > physics topics, like top mass, single top etc, last the pT turnon . > I suggest that John takes care of the Higgs (he is doing that anyway for the > SUSY/Higgs workshop I think (?)). I can pursue the top mass precision > question further. Maybe Hal can look at the single top. For the turn-on > curve, we have to manipulate the trigger simulator to use the STT pT rather > than the CFT pT at level2. Maybe Dan and Brian can do that. These studies > don't have to be too detailed. > > As far as interpreting PK goes your guess is as good as mine. I was just > trying to convey the spirit of some of the conversation. I don't know the > answer - I don't see why an MRI proposal should affect our chances of > getting money from DoE? I suggest we pursue both alternatives. > > Ulrich > > > From heinson@phyun0.ucr.edu Fri Nov 13 09:54:32 1998 Date: Wed, 4 Nov 1998 11:04:13 -0800 (PST) From: Ann Heinson To: "Horst D. Wahl" Subject: Re: STT and single top production UC Riverside Horst, The paper I wrote with Edward Boos and Sasha Belyaev has a detailed estimate, including systematic errors as well as statistical, for the predicted sensitivity to see single top in the l+jets/tag mode. I could extend this estimate to include the hadronic channels, but only at the spreadsheet level - I don't have a model of the background in the allhadronic channel to do detailed MC studies. The paper is PRD 56, 3114 (1997). Regards, Ann From heinson@phyun0.ucr.edu Fri Nov 13 09:54:55 1998 Date: Wed, 4 Nov 1998 11:17:38 -0800 (PST) From: Ann Heinson To: "Horst D. Wahl" Subject: Re: STT and single top production UC Riverside Horst, The preprint version of the paper (almost the same as the final one) is at hep-ph/9612424 . If you have access to the PRD server, (if FSU has subscribed to the online version) then you can get the actual paper in PS or PDF formats from there. My gut feeling is that using the allhadronic channel will more than double the available statistics for single top, and so it is certainly worth studying. I can start the new calculations here - I have the spreadsheet set up, and explaining to a student not at Riverside what is needed is not always straightforward. Often there are assumptions which get missed in the remote dialogue. Regards, Ann From wahl@sg1.hep.fsu.edu Fri Nov 13 09:55:11 1998 Date: Wed, 4 Nov 1998 08:33:00 -0500 (EST) From: "Horst D. Wahl" To: ann.heinson@ucr.edu Subject: STT and single top production Hello Ann, At the PAC meeting on Oct 23, although the reaction was generally favorable, we were given to understand that our physics case was not quite strong enough -- in particular not quantitative enough. The committee (which is loaded with neutrino, B-physics and e+e- types), apparently did not appreciate the importance of being able to improve background rejection at the trigger level. They kept asking questions like: "How much bigger is your chance of discovering the Higgs with this trigger than without it", etc. We are expected to give such "more quantitative answers" at the next PAC meeting in January. One of the channels of interest is single top production. As you know, Terry Heuring had done a study of single top production, with the conclusion that having an STT will help keep the trigger rate down, while maintaing good signal efficiency. But this is not good enough for the PAC. The question which they would like us to answer is something like: * What is the significance with which we can see eviddence for single top production with and without STT? * What is the precision with which we can measure the single top production cross section and V_tb (with and without STT) * What is the improvement from being able to trigger on the all-jets mode? My questions to you: - Are there any studies about expected single top meassurements in run2? - Has there been a study which examines the value of b-tagging in single top studies? - Is there any hope to separate single top from the background in the all-jets channel? - do you have any other words of wisdom to offer on this? Regards, Horst From HARRY@FSHEWK Fri Nov 13 09:55:47 1998 Date: Thu, 5 Nov 1998 20:58:17 -0500 (EST) From: HARRY@FSHEWK To: wahl@sg1.hep.fsu.edu Cc: connolly@fsheb2, HARRY@FSHEWK Subject: RE: STT studies for top to all-jets Dept. of Physics, Florida State University, 5-NOV-1998 Hi, Allow me to "think aloud"! The STT can do one, or both, of two things 1) improve the trigger efficiency; 2) enrich an event sample. Obviously, if a trigger efficiency is already high, say above 90%, there is not much to be had from the STT. For example, in the all-jets channel I believe the trigger efficiency was indeed above 95%. Therefore, I would not expect a gain here. Unless, of course one were forced to prescale the trigger. Then the efficiency for all-jets could plummet. In which case the STT would be crucial. Therefore, what we need to understand (guess!) is how likely is that we shall be forced to prescale the trigger and by how much? I confess to have no insights about this question! So the "off the top of my head" guess is: if we don't prescale then I would expect no gain in signal/noise ratio for all-jets (and therefore no improvement above what is anticipated for the mass measurement), though of course we would have a more manageable sample because of the enrichment afforded by the STT, but if we prescale the 5-jet trigger then we would need the STT to maintain the current efficiency. Harrison From wahl@sg1.hep.fsu.edu Fri Nov 13 09:56:22 1998 Date: Fri, 6 Nov 1998 11:54:38 -0500 (EST) From: "Horst D. Wahl" To: Dan Karmgard Subject: SUSY generation Hello Dan, The new measurements of B(b to s gamma) which is now = 3.15 x 10^-4 do infact rule out the point chosen by Doug Norman, and in fact reduce the probability of seeing SUSY at the Tevatron. The paramaters that we would like are the following: Tan beta = 2 and 5 sgn(mu) = +1 (not negative as Doug did) m_0 = 200, m_1/2 = 125, A_0 = 0 Howie will look further into this, and possibly come up with a better set sometime, but he thinks the values above are OK to start with. Regards, Horst From wahl@sg1.hep.fsu.edu Fri Nov 13 09:56:33 1998 Date: Fri, 6 Nov 1998 11:54:38 -0500 (EST) From: "Horst D. Wahl" To: Dan Karmgard Subject: SUSY generation Hello Dan, The new measurements of B(b to s gamma) which is now = 3.15 x 10^-4 do infact rule out the point chosen by Doug Norman, and in fact reduce the probability of seeing SUSY at the Tevatron. The paramaters that we would like are the following: Tan beta = 2 and 5 sgn(mu) = +1 (not negative as Doug did) m_0 = 200, m_1/2 = 125, A_0 = 0 Howie will look further into this, and possibly come up with a better set sometime, but he thinks the values above are OK to start with. Regards, Horst From wahl@sg1.hep.fsu.edu Fri Nov 13 10:15:41 1998 Date: Fri, 6 Nov 1998 12:05:52 -0500 (EST) From: "Horst D. Wahl" To: HARRY@FSHEWK Cc: connolly@fsheb2 Subject: RE: STT studies for top to all-jets Hello Harrison, I agree with you, and this is the conclusion that Terry reached -- the STT allows reduction of the background, but, if the luminosity is low enough and with ideal beam conditions, and if we run at 132 ns bunch spacing, and if we understand our trigger rates, then this reduction is not needed. If these assumptions are not correct, then we might have to prescale and therefore lose efficiency. The questions that I meant to ask (but maybe did not make clear) are the following: - is there any way to make a guess as to whether there is any hope of recognizing single top events in the all-jet decay mode above a two-jet background? - if yes, how much would this gain us in the V_tb measurement? - If we lose efficiency because of trigger rate limitations, how would that degrade the measurement (or how much would having more events improve it)? The problem is, of course, that thesse questions are not easy to answer. Is there any simple way of studying this or is there some not too irrational way of making an educated guess? Regards, Horst From WEERTS@pa.msu.edu Fri Nov 13 10:15:58 1998 Date: Thu, 12 Nov 1998 14:37:49 -0500 From: Harry Weerts To: evans@fnal.gov, wahl@fsheb2, heintz@fnal.gov, meena@fnald0.fnal.gov, hobbs@fnal.gov, christenson@fnal.gov, tuts@fnal.gov Cc: weerts@pa.msu.edu, mont@d0sgi0.fnal.gov Subject: PAC letter re P-908 (STT). Resent-Date: Thu, 12 Nov 1998 14:37:34 -0500 (EST) Resent-From: wahl@FSHEB1 Resent-To: wahl Fermilab , 12-NOV-1998 Dear all: here is the letter we received from the director concerning the STT proposal. Our website is down because of a power outage. It will be posted later. Harry --------------------------------------------------------- From: SMTP%"Jackie_Coleman@qmgate.fnal.gov" 12-NOV-1998 14:25:50.00 To: WEERTS CC: Subj: letter re P-908 Return-receipt-to: Jackie Coleman Date: Thu, 12 Nov 1998 13:20:07 -0600 From: Jackie Coleman Subject: letter re P-908 To: Harry Weerts November 11, 1998 Hugh Montgomery D0 MS 357 Hendrik Weerts Dept. of Physics & Astronomy Michigan State Univ. East Lansing MI 48824 Dear Mont and Harry, Thank you for the presentation on the new proposal for a Level 2 Silicon = Track Trigger for D0 (P-908) at the recent PAC meeting. The PAC's = comments follow: "P-908 - D0 (Montgomery/Weerts) The D0 Level 2 Silicon Track Trigger (L2STT) would trigger on the = detached vertices of b-decays, thereby extending D0's reach for high-pt = physics. The group showed, for example, that such a trigger would = improve measurement of the top-quark mass by using a large sample of Z -> = bb-bar decays to improve the b-jet energy resolution. This trigger might = benefit many other analyses. The L2STT proposal is very interesting and the Committee encourages the = collaboration to carry out more complete studies of its capabilities. = Such studies should include the impact on b-jet energy resolution that a = large sample of Z -> bb-bar decays would provide and the increase in = signal over background of a few important high-pt physics processes. The = Committee would like to hear a presentation of these studies at its = January meeting. The Committee encourages the collaboration to develop this proposal = aggressively. The Committee notes that the Laboratory's funds for new = projects are very limited and the availability of unused contingency is = very unlikely, and urges the collaboration to seek outside funds." Please plan on making a presentation to the PAC on the studies requested = above at the January 15-17 meeting. You should also present a detailed = plan on how these upgrades are to be funded. Written documentation = should be submitted no later than Tuesday, January 5 so that it may be = sent to the PAC before the meeting. Sincerely, John Peoples cc: A. Kronfeld K. Ellis A. Firestone J. O'Fallon