Dear Collaborator,
I am happy to distribute another progress report on work on-going at the institutuions. This is a very busy time and I appreciate the effort
of those who took the time to contribute to this collection of on-going work and progress. I hope to have the next gathered just before QM
and the subsequent one on or about August 13.
regards
Flemming
------------------------------------------------------
Flemming Videbaek
Physics Department
Brookhaven National Laboratory
tlf: 631-344-4106
fax 631-344-1334
e-mail: videbaek@bnl.gov
Progress report from Norway
_________________________________________________________
Spectra and yields - Jens Ivar:
Currently working on:
*Getting the yields right at the MRS. The yields are calculated
without curve fitting and extrapolation, thus a somewhat different
approach then the one performed by Peter a.o. Latest numbers for
pions at 5% central at midrapidity are 222+-5 (pi+) and 224+-6 (pi-),
t.e. acceptance, decay and absorption corrected numbbers. The
relatively high uncertainty above as well as spectra of kaons and
protons are most probably subject to the low statistics in the
sample I've used. For higher statistics kaon and proton spectra
show nice behaviour, so I'll report on their yields as soon as
possible.
* Finishing my estimation of effective temperature.
Future plans:
* Cut and paste to overlap different settings in the MRS, most
probably y = 0.5 and y ~ 1.
* Apply additional corrections
* Proceed in a similar way in the (F)FS.
___________________________________________________________
Efficiency calculations - Truls:
Currently working on:
* Truls has rewritten the efficiency code BEAT to a bratmain compatible
framework, using "package" classes BrEffGeantModule and BrEffRecoModule
to take care of the multiple inputs and track tables. At present
debugging and testing.
* Trine rechecked the digitization parameters for TPM1, TPM2,
T1 and T2, comparing to experimental data with calibrated drift
velocities.
Future plans:
* Produce tracking efficiency results for MRS and FFS
* Make poster for QM according to abstract titled: "The BRAHMS
spectrometer efficiency"
* Implement the time-of-flight detectors in efficiency estimates
in BEAT
* Study the TPC two-track resolution
___________________________________________________________
Lambda project - Elin, Bjørn, Trine:
* Bjørn finished his QM poster: "Possible future measurements of
forward rapidity lambdas at RHIC", as announced to the collaboration.
Currently working on:
* Elin and Bjørn have made DSTs containing TPM1 tracks for 35,
40, 60 and 90 degrees.
* No lambda signal observed yet with the new version of the analysis
chain. Elin and Trine are going critically through the algorithm
and the coding - a few bugs were identified yesterday, but there are
still things we don't understand.
* Estimating acceptance for Lambdas in MRS as a function of
momentum, to find the approximate number of Lambdas we expect
to observe.
Future plans:
* Make poster for QM according to abstract titled:
"Measuring lambdas at midrapidity with the BRAHMS spectrometer"
* Extract Lambda and anti-Lambda yields for the MRS
___________________________________________________________
High-p_T spectra - Mads:
Currently working on:
* Gaining experience with FS analysis chain
Future plans:
* Extract high-p_T spectra of identified particles in the FS
___________________________________________________________
Short report on Activities in the HEHI-NBI group Week 26, 2002.
During these rainy, slightly chilly summer days we are proceeding along several
fronts. The following is a (very) brief summary of this activity.
1. MRS Analysis: Peter has continued, in cooperation with EunJoo, to
look at spectra in the MRS. His latest efforts were stymied by a
problem in the global tracking (the appropriate matching parameters
were only picked up for some runs, not all). The problem has now
been corrected and the global tracking redone. The dsts are being
produced (even as I type!), but none of this was done before Peter
escaped to a week of vacation. In Rome, with Maria. We are all
very happy that he was able to take vacation, no, really, we are
not at all jealous.
2. A bit more speculative than the foregoing, but we have tried a bit
to push Bjørn Samset's lambda analysis in the MRS. It is probably
too early to punt on this, but we have found no evidence of a
signal and will not continue this project until after QM.
3. In the FS,
Djamel Ouerdane is starting to get some nice looking pi and K
spectra. These results will be made available to the collaboration
as they mature in the coming days.
4. In the past two weeks, we have (more or less) completed the
calibration of drift velocities (at least for setting for which it was
possible, it is not possible for the high pt runs at 12 degrees since
there are simply not enough tracks).
5. We have produced a (very nearly) complete set of dst's for Au+Au
runs 5361 and higher. At the moment, these are spread over
several directories at BNL, but will be consolidated, and a
message will be sent to the collaboration.
5. Claus Ekman is finalizing the results for the 200GeV ratios paper.
Work on the draft is proceeding nicely, and we are quite close to
having a very nice story. And, if you don't agree, it is up to
you read the draft and comment upon it!!
6. High pt. In addition to the projects mentioned
above, we (primarily Claus) are trying to work up the high pt
forward data. He has also looked into the MRS high field data and
has produced a couple of spectacular plots, which I am sure he will
share with you when he is ready.
7. Peter C. and David S. are preparing a ratios poster for QM. Well,
they would be, but they are both on vaction. David is at Roskilde
festival in the rain and mud, so we really aren't jealous of him.
8. IGB is thinking hard about starting to plan the QM plenary talk.
Sadly, the niether Denmark nor the US went through to the finals,
so I should have something early next week. I am (still!!) waiting
for any input at all from my many collaborators. If any of you
care to make suggestions, send plots, ideas, etc. you can contact
me at bearden@nbi.dk.
BNL
The decay and absorption correction factors evaluation by EJK for MRS at 90 and 40 deg has been completed.
Work to reconstruct the earlier runs before 5361 has started. This needs a fair amount of preparation since many calibrations are not done for those runs.
1 TPC pad status for run4532-run5360 : 15 runs calibrated, and commit
to data base
2 preparation for analysis : Pid and making tracktree for
tun5361-run5983
3 data reduction for local tracking : run4532-5360
The work to make correction factors for the FS has started, and discovered several problems in geometry in BRAG. The code involves full digitization, track reconstruction and matching. The factors are expected to have much less p dependence that in MRS.
The order for the replacement silicon wafers has gone out. The new DC distribution system will need additional HV modules for the L1458 system; information for these has been gathered.
The design for a VME trigger up/donw AND + OR module has been completed and the detailed layout started.
Dana has investigated tubes and properties as replacement for ZDC tubes to achieve better time resolution for online trigger purposes see brahms/private/detectors/zdc for additional information (powerpoint file).
In the earlier part of the reporting period, the slewing software for MRS (and FS) was completed and calibration committed (for MRS).
Analysis is being carried out with the final global track and dst data-files for both FS and MRS. This involves cross-checks of the data quality as well as preparation for generating differential cross-section using both the software developed by Peter, Djamel and Claus, and the alternate track-based acceptance by JHL.
Progress report at TAMU:
pp:
Work on pp continues. I accomplished a slewing correction for H2 in pp
that I believe. I have put a list of resolutions achieved on
http://Cyclotron.tamu.edu/hagel/brahms/ProgressReport-28-Jun-2002/Tof2CalCheckResults
There is an overall sigma (in ns) which shows the overall resolution to
be between about 85 ps for the best tubes and 129 ps for the worst. In
the 4th column, I subtracted out an assumed 60ps resolution for td1 to
get the slat resolution and one can see that the slat resolutions with
slewing range from 60ps to 115 ps.
If you care to see the resolution plots, they can be found at
http://Cyclotron.tamu.edu/hagel/brahms/ProgressReport-28-Jun-2002/TOF2Resolution.eps
I then made a DST file and then a plot beta vs P and got the plot shown at
http://Cyclotron.tamu.edu/hagel/brahms/ProgressReport-28-Jun-2002/h2BetaVsP.gif
and mass2 vs P at
http://Cyclotron.tamu.edu/hagel/brahms/ProgressReport-28-Jun-2002/h2Mass2VsP.gif
I think we have reasonable resolution of pi/K up to about 4 (although
that is not quantative, just from looking at the 2d plots). That is
quite a bit lower than the 5.8 we say in the NIM paper. A more
quantative analysis might show that it is somewhat higher.
These slewing corrections and offsets are not yet committed into the DB.
This will happen soon.
I am fairly satisfied this is in order. Work can now begin on surveying
the pp runs and then to begin to extract some ratios.
ZDC:
Andrei has done some calibrations and committed them to the DB as
indicated by his e-mail messages to the list.
Progress Report U.Kansas
During the past two weeks, the KU group has focussed on: a) Getting Hiro
finished, b) developing an arrangement for mounting phototubes to the new
MRS Cherenkov detector, c) getting final MA calibration parameters for the
200 GeV data runs, and d) obtaining more realistic simulations for different
experimental arrangements to obtain reaction plane information and to
determine where the Cherenkov photons end up in the new MRS Cherenkov.
In somewhat more detail:
a) Hiro has pretty much finished his first draft and is now working on
incorporating his Advisor's comments, with comments available for about 90%
of the draft.
b) Updated drawings showing a possible arrangement for holding the
phototubes can be found at:
http://www.phsx.ukans.edu/~sanders/Cherenkov
If you have a copy of AutoCad, you should be able to open the .dxf file to
look at the details of the design.
Also, the material has arrived for construction of the front box for the
Cherenkov. The KU shop has begun work on this construction.
c) Final pedestals for SiMA and TMA should be available by the time this
report gets distributed. During this analysis we are also looking for any
potential calibration problems that might affect our centrality
measurements.
d) James Norris and Carissa Hill are struggling with their respective
computer codes...
Kraków group progres raport.
1. Radek Karabowicz defended his master thesis entitled "Particle Track
2. Identification in the Drift Chambers of the BRAHMS Experiment". Implementation of Radek's software into the BRAT is in progress.
3. The DCs calibration of GlobalTdcOffset and DriftTime parameters are completed for runs 5258+. The GlobalOffset was found for runs 5074-5257 and the search for the DriftTime is in progress. The second iteration for both GlobalTdcOffset and DriftTimeshould be finished this week.
4. Analysis Note on the cross talk is in preparation.
5. The HV splitter project has been approved and the construction started in our machine shop.
This archive was generated by hypermail 2b30 : Wed Jul 03 2002 - 21:38:47 EDT
