Hi Dave,
We tried to include all the simulation details in the series of documents that we produced for the Science Review. All can be found on the TWiki including the FVTX Proposal, and the two review response documents (found under Meetings and Presentations, July 9-10 DOE Review) which include a reasonable amount of follow-on simulation work. I mention that there are various incantations of the plots available primarily because, even though we put what we believe are appropriate representative plots in our documents, there are still often requests for slightly different versions - which can be made or culled from other presentations if requested.
Melynda
David Winter wrote:
hi melynda and all:
i am very curious about this 1B number. could you remind me where these events are? back when the sci rev response was being worked on, i remember numbers like 1B being thrown around, but i didn't fully appreciate just how difficult it is to "fully reconstruct" as many as 10M (which is what we are in the process of doing at nevis). for instance, i am estimating that the output for our (10M) sample will amount to ~1T... and only after making the decision to ditch the reconstructed dsts.
so, could you go into a little more detail about this sample and the reconstruction? it would greatly aid in clarifying some confusion, i am sure. it may also help us, in the off chance we are doing something incorrect.
i also would like to suggest that all the work that went into those studies be codified in an analysis note. clearly a lot of work and thought went into it, and it's a challenging task to understand b/c separation issues for those that aren't on the front lines. an AN would go extremely far in helping non-fvtx-ers to understand the picture. and it would be a lot easier than trying to google around for various incarnations of plots. :)
finally, i have to agree with the sentiment that p+p be focused on first. now having dealt with both pythia and hijing in the last 6 months, i sure would like to be confident of p+p results before scratching my head over hijing.
dave
Melynda Brooks wrote:
Dear Barbara and all,
I'm not sure what technical difficulties you heard about, but from the FVTX end we think there are no technical difficulties but we have asked for a little more time to finish checking latest PISA geometry changes. As you know, we basically already performed this full simulation effort once before in preparation for, and in response to questions asked at our FVTX Science Review in July 2007. For that effort, we generated approximately a billion events of various flavors (using PYTHIA primarily), fully reconstructed them, extracted physics plots, and performed a b/c separation analysis using reconstructed info. So we have exercised all the pieces before but with older geometry. What we didn't have was the mixed in HIJING backgrounds, which is one of the reasons we are especially interested in the full blind analysis effort. We also did not have VTX-reconstructed vertices nor event vertices which originated away from 0,0, which we are interested in studying.
When the blind analysis chain and output format was determined through Tony/Axel's phone conferences, we (Zhengyun primarily) translated our previous macros into macros that would accept blind analysis input DSTs and output pdsts. Our main efforts right now are to try to verify that we really have all the PISA geometry changes we need to reflect the current design (a seemingly continuous effort) and to make sure that the new reconstructed distributions are understood.
As for DCA distributions, the reconstructed DCAs were shown in various venues also around the science review time. There are various versions because the DCA distribution is multi-dimensional, they are interesting with and without various cuts... but some representative plots of them can also be found in our science review documents, e.g. in our last response document which I put at: https://www.phenix.bnl.gov/WWW/p/draft/brooks/fvtx/ReviewJuly07/responseQA3.doc. Other incantations of the plots are also available.
Melynda
Barbara Jacak wrote:
Dear all,
I would like to, once again, concur and amplify this request from
Jamie. It is a very important proof-of-principle and first step to quantify
our c/b separation capabilities in p+p collisions using PYTHIA events.
When we last had an email exchange about this, there were technical
difficulties in handling and analyzing the events that precluded addressing
this question. Are those now under control? If so, then this analysis
could take place in parallel with generation of HIJING background
events for Au+Au performance studies. If not, what is still missing?
best regards,
Barbara
On 1/14/09, jamie.nagle@colorado.edu <jamie.nagle@colorado.edu> wrote:
Hello Sasha and Other Blind-ers,_______________________________________________
I had made the suggestion many months ago, but think given the time
schedule, it might be worth re-visiting. The suggestion was that the
blind analysis should start with the proton-proton 200 GeV case. One can
just run PYTHIA events and adjust the charm and beauty cross sections (and
perhaps a slight change in the ratio of different D/B states). This will
lead to a much shorter time schedule for a result - since one does not
need lots of HIJING events with full response, disk space, recon. time,
etc.
At the time, the assertion was that separating c and b in the
proton-proton case was easy, and not necessary to test. I believe there
are enough concerns that this should be done, and done first - to have a
result sooner, which then builds confidence. After that, the full Au-Au
case can be done. I would appreciate it if this can be discussed and
decided on.
Also, Bill was explaining how there is often a mis-conception that because
the D has a c\tau that is ~x3 different than the B c\tau, the DCA
distributions will be very different. The problem is that the distance
the meson travels before decaying is \gamma c \tau. Thus, if one selects
a fixed momentum electron or muon (and assume it carries the same momentum
fraction from the parent), the \gamma is ~x1/3 for the B meson. Thus the
\gamma c \tau is quite similiar. Everything is in the decay kinematics.
I was reading Analysis Note 727 (Eric Vazquez, David Winter), and was
wondering if someone can post or point to the DCA distributions for
electrons within |\eta| < 0.35 as a function of pT of the electron from D
mesons and B mesons (separately). What I would like to see is the DCA
assuming an absolutely perfect detector - basically just the distributions
straight out of PYTHIA for example (no detector response at all). I make
the same request for the same distributions for the pseudorapidity
coverage of the muon arms (fVTX). It would be good for the electron and
muon cases to see these plots in fine bins in pT going from pT = 0.0 -
10.0 GeV/c. Presumably at some high enough momentum, the decay product is
mostly co-linear with the parent.
I realize there are much more advanced studies already under way (and I
have seen some sub-sample of the plots mentioned above), but believe it
would help me and others in PHENIX to see the basic kinematics of the
problem over the full range of momentum.
Sincerely,
Jamie
+--------------------------------------------------------------------------------+
|| James L. Nagle EMAIL: jamie.nagle@colorado.edu
||
|| Associate Professor of Physics PHONE: (303) 735 - 3560 (OFFICE)
||
|| University of Colorado at Boulder PHONE: (303) 735 - 2996 (LAB)
||
|| FAX: (303) 492 - 3352
||
|| MAIL: Department of Physics
||
|| University of Colorado at
Boulder ||
|| 390 UCB
||
|| Boulder, CO 80309-0390
||
|| WEB:
http://spot.colorado.edu/~naglej ||
+---------------------------------------------------------------------------------+
On Tue, 13 Jan 2009, Alexandre Lebedev wrote:
Hi all,_______________________________________________
As we agreed at today's meeting, I've created a wiki page for
the blind analysis challenge in order to collect all relevant information.
The page is:
https://www.phenix.bnl.gov/WWW/offline/wikioffline/index.php/Blind_Analysis_Challenge_for_FVTX/VTX_Detector_Upgrades
You can also access it from the main Phenix offline wiki page (at the
very bottom).
I would like to encourage everyone to contribute to this web page. Doing
this is very easy, and the more information we have there, the easier it
will
be for everyone to work. I already put some stuff there, and created some
headings, but everyone is welcome to modify and add to this web page.
Sasha.
------------------------------------------------------------------------
Dr. Alexandre Lebedev phone: (515)-294-8699
Department of Physics and Astronomy, fax: (515)-294-6027
Iowa State University,
http://www.public.iastate.edu/~lebedev
Ames, IA 50011-3160 lebedev@iastate.edu
------------------------------------------------------------------------
_______________________________________________
Phenix-vtx-l mailing list
Phenix-vtx-l@lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/phenix-vtx-l
Phenix-vtx-l mailing list
Phenix-vtx-l@lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/phenix-vtx-l
Phenix-fvtx-l mailing list
Phenix-fvtx-l@lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/phenix-fvtx-l
--
Melynda Brooks email: mbrooks@lanl.gov
MS-H846, Group P-25 office: A102, Bldg. 1, TA-53
Los Alamos National Laboratory phone: (505)667-6909
Los Alamos, NM 87544 FAX: (505)665-7920
_______________________________________________Phenix-fvtx-l mailing list
Phenix-fvtx-l@lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/phenix-fvtx-l
_______________________________________________ Phenix-fvtx-l mailing list Phenix-fvtx-l@lists.bnl.gov https://lists.bnl.gov/mailman/listinfo/phenix-fvtx-l