Dear Collaborator,
As we agreed upon at the recent collaboration meeting we would re-institute
the activity reports. Thanks to diligent collegues I am happy to enclose the
first report.
The reports are listed by institutions essentially as they were received,
and very limited editting has been done. Please direct questions to the
correspondents
directly. I hope a next report can be circulated in about 2-3 weeks.
regards
Flemming
Activity Report
This report covers activities mainly since the Collaboration meeting in
Copenhagen on May 21-24.
BNL (F.Videbaek)
--------------------
Experimental Area and Hardware.
Magnet Mapping
The excitations curve mapping of all magnets have now been completed; The
relation between Hall probes, current and field will be finalized (Ramiro)
and the information given to Kris so this eventually can be used in the
analysis. The probe jigs will be kept in place in case additional
measurements are needed. The water system will be shut down.
TPC
Due to the mapping the TPC's have been moved on the stand to make space for
the jigs for the magnet mapping. Thus before the next run a new survey ahs
to be performed. A few broken wires in T1 and T2 are being repaired.
Trigger Electronics
A schematic design of a VME modules that can perform a masked AND + OR
function of 16 channels tof Up/down slats to be used for a MRS spectrometers
trigger, and replace the NIM electronics for H1 and H2 has been developed
(Bob Scheetz). The detailed design and simulation will be done over the next
month, after which the layout can start. The implementation for TOFW is
envisioned to have a NIM/ECL modules and a VME crate with 8 such modules
will be situated on the Platform. Some programming (in style of slow control
software for Power PC processors) is needed.
Analysis
Drift velocity calibration.
A complete calibration using existing software for MRS has been performed by
EJK., and the values entered into the Database. It has though also become
clear that this procedure for average Vdrift is not sufficient and
additional thought and work has to go into this. For the purpose of QM we
should probably live with the non-optimal values, and apply run dependent
vertex and matching cuts, as well as fiducial cuts. For the final papers and
for running next year this outstanding problem that has cost lost of effort
has to be solved. EJK has posted some result on the Web (see list server
message).
Efficiencies and acceptance corrections.
Extensive MC calculation involving full digitization and track/PID
reconstruction has been done for MRS at 90 and 40 degree to parameterize the
efficiency due to multiple scattering and decay correction. The work is
almost complete and a parameterization will be available to be used in the
generation of dN/.dpt and dN/dmt spectra. As expected the decay correction
for pions is smaller than the simple decay-length correction by about 1/3 (a
10% effect at low pt (~0.4 GeV/c)
Tof slewing Correction.
The tof slewing corrections methods developed by JH and Dana is being
incorporated into the brat module framework by FV. As often it is to be
completed within the next day, but is actually working reasonable well and
is being tested on a set of 60 deg runs. (5609-5650) and on the (5940 series
at 90deg 6B).
Once added to brat additional calibrations will have to be made.
Analysis
NBI (I.Bearden reporting)
--------------------------------
Short report on Activities in the HEHI-NBI group Week 24, 2002.
During these wonderful summer days we are proceeding along several
fronts. The following is a (very) brief summary of this activity.
1. MRS Analysis: Peter Christiansen is making progress with the
acceptance corrections. The final word on various corrections (for
absorption, decay, "slow protons", etc) has yet to be said, PC is
working closely with EJK on this. The expectation is to get final
particle yields in the next (very few) weeks. The first priority
is to look at 90 and 40 degree data, and then fill in other
settings as time permits.
2. A bit more speculative than the foregoing, but we are also trying
to push Bjørn Samset's lambda analysis in the MRS. It is not clear
at present whether or not this will lead to a positive signal.
3. In the FS, we are striving to obtain particle spectra.
Djamel Ouerdane is putting the final touches on acceptance
corrections for the FS, the first goal is to get pion spectra
(since we have several settings in which one can obtain a pion pt
spectra in a narrow rapidity range). After this is done, we should
be able to combine different settings to obtain K and proton
spectra. As part of this effort, Pawel Staszel is investigatining
the FS efficiency. Here the goal is to parameterize the efficiency
as a function of Centrality, x, and alpha_x in each tracking
detector. This should give a pretty complete picture of the
efficiency of the FS, appart from the Cerenkovs which Claus Ekman
has worked on previously.
4. In addition to the above, we (mostly David Sandberg) are trying to
produce a more complete set of drift velocity calibrations for T1
and T2. As this work proceeds, we are redoing the data reduction
and producing new dsts. The latest also include a new calibration
of the T1 and T2 pads, which should improve the FS tracking,
though we don't yet know how large the improvement will be.
5. Claus Ekman is finalizing the results for the 200GeV ratios paper.
This should probably go pretty fast if we want to beat the bad
guys!
6. High pt. In addition to the projects mentioned
above, we (primarily Claus) are trying to work up the high pt
forward data. By early next week, we hope to have an idea how
things look for the 12 degree data, and how much effort we should
put into the 3,4 degree high field data. The latter is maybe more
a question of where 'high-pt' begins.
7. IGB is starting to plan the QM plenary talk.
The ultra-preliminary outline is to talk about:
*multiplicity results
*ratios (briefly, we have also a ratios poster)
*spectra and yields (the best from the parallel talks, plus what
doesn't get emphasized in these...)
He would like to stress that any and all input from collaborators
is welcome (and as can be seen from the outline, it is also
necessary!). The ambition is to have a 'rough draft' of the talk
by 30. June, though if either Denmark or the US go through to the
World Cup final this date could slip, so please send your thoughts
to bearden@nbi.dk.
TAMU
----------
Analysis (Kris Hagel)
I have spent the last several weeks at TAMU gauging the quality of the pp
data.
After debugging the configuration scripts for track matching, particle
identification in the BFS was achieved. It was quickly established that the
TOF1 and TOF2 time offset calibrations were not in order. Effort was made
to
understand and execute the calibration procedure developed by Djamel. In
the
end this worked very well, but this procedure makes very optomistic
assumptions
about what is in the file being read. I had to spend a fair amount of
effort to
understand that and then to put in the proper modules to generate the tables
that my particular file did not have.
I generated a set of TOF1 and TOF2 time offset calibrations which, when
used,
generate much better pid spectra. The "shadow" in TOF2 is now absent and
the
pid lines in TOF1 now correspond to the theoretical lines. The pi/K
separation
in TOF2 at least on the 2d plots does not appear to go as high as we say in
the
NIM paper. I should note that I am not using slewing in generating these
plots. I will wait for the BNL slewing corrections to be implemented in
BRAT.
I am now checking the resolution of the detectors without slewing using the
new
calibrations I extracted. I have not yet succeeded, but am probably close.
I
ran into yet more problems by downloading Pawels new modifications to the
BrDCTrackingModule. Using MySqlMode, it is giving some errors. I have not
followed it far enough to "blame" anyone. So far, I still consider myself
guilty of doing something wrong.
Kansas (S.Sanders)
--------------------------
Drawings for the mid-rapidity Cherenkov detector are approaching completion.
The
current drawings can be viewed at
http://www.phsx.ukans.edu/~sanders/Cherenkov . The front box for the
Cherenkov has been submitted to the KU shops with anticipated completion of
this front box by
mid-July. The final details for the back, mirror box, including support for
the
phototubes, still need to be completed. The current design has been
implemented in
BRAG as the C4 detector.
A new student has started work on flow/reaction plane simulations. Although
at an early stage,
the goal of this project is to determine if there is a more optimal mounting
arrangement for the Si detectors
to establish reaction plane information. We also hope to explore using
scintillator detectors around the
beam pipe in a configuration suggested by JH.
There has been little work on the MA calibrations, with our emphasis placed
on getting critical parts for the
MRS Cherenkov into the shops. Now that the shop has begun construction, we
expect to again
focus more attention on completing the MA calibrations.
Kraków group progres raport (Z.Majka)
1. Radek's software for the particle track identification in the drift
chambers
has been tested. We obtained a significant improvement of the drift chamber
efficiency. The implementation of the procedure into the BRAT will be done
soon.
2. Analyses of the cross talk is being finalized.
3. The DCs calibration of GlobalTdcOffset and DriftTime parameters is
completed for runs 5361-5594 and continues for 5594++. It is performed in
two steps using both Pawel's self-convergent procedure (DcTrack.C) and
Krakow's shell scripts.
4. The design of the HV splitter for drift chambers has been completed.
(note added in editing /fv: The design is presently being reviewed by
B.Scheetz, and will most likely also have to be review by RHIC Safety
Committee once details are clarified )
Oslo/ Bergen (Trine Tveter)
------------------
Jens Ivar:
Currently working on:
* Yields in the MRS @ y=0, y=0.5 and y~1. More specifically
normalization problems accounting for yields a factor of 2
above the Phenix 130GeV results. (Some progress since the NBI
collaboration meeting.) K/pi ratios.
* Decay and cut corrections for kaons in MRS.
Future plans:
* Extract yields and K/pi in FFS, if time allows also BFS
* Decay and cut corrections for kaons in FS
* Apply tracking, reconstruction, decay and cut corrections to
both spectrometers
* Make poster for QM according to abstract titled:
"Rapidity distributions of charged kaons and pions at sqrt(s_NN) =
200GeV Au-Au collisions"
___________________________________________________________
Bjørn:
Currently working on:
* Lambda analysis in the MRS - trying to optimize cuts and
improve mixed event background
* Investigating possibility for Lambda / anti-Lambda detection in
FS, using the forward spectrometer arm together with ALICE SDD
planes
* Extraction of spectra in the FS, testing of cuts.
Future plans:
* Getting married
* Make poster for QM according to abstract titled:
"Possible future measurements of forward rapidity lambdas at RHIC"
__________________________________________________________
Truls:
Currently working on:
* Debugging of the standalone efficiency program BEAT, problem
still not solved. Desperately awaiting feedback from experts!
* Volunteered for the calibration task force during the
collaboration meeting, and eagerly waiting for instructions.
Future plans:
* Produce tracking efficiency results for MRS and FFS
* Implement the time-of-flight detectors in efficiency estimates
in BEAT
* Make poster for QM according to abstract titled: "The BRAHMS
spectrometer efficiency"
* Study the TPC two-track resolution
___________________________________________________________
Elin:
Currently working on:
* Estimating acceptance for Lambdas in MRS as a function
of momentum, to find 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
Bucharest (A.Jipa)
-------------
We are able to obtain multiplicity information from global
detectors (BBC, tiles, ZDC) using our computing facilities. I sent you
few months ago a short abstract for a work which was presented at our Annual
Scientific Session. It was accepted for publication in Romanian Reports in
Physics . We selected only the
events with interaction vertex in the range [-45 cm, +45 cm] for Au-Au
collisions at 130 A GeV. The average multiplicity per pseudorapidity bin
is 670, at eta = 0.0. An significant increase appear for /eta/ = 2.0
(around 940 per pseudorapidity bin. Also, some uncovered bins - between
2.2 and 2.7 appeared. The situation changes when a larger range in the
vertex interaction is chosen, and similar distribution with those
presented previously are obtained.
- A important step in the trajectories reconstruction was made in the
last two weeks. We can obtain trajectories. Now we try to take into
account the presence of the magnetic field in different magnets. Catalin
Ristea and Sorin Zgura will try to summarize soon the first significant
results.
- We obtained experimental and pionic and kaonic temperatures from the
transverse mass spectra using the methods proposed at the Copenhagen
workshop from March. We used the predictions of the UrQMD code for time
evolution of collision and estimated energy density. We obtained
densities ten times higher than the normal energy density, and a proper
time around 20 Fm/c. This result is very interesting taking into
account different predictions for QGP's lifetime. An other interesting
result is related to the behaviour of the kaon rest masses in
dense nuclear matter. These results will be included in the work
that will be presented by Oana RISTEA at the General Conference
of EPS from Budapest, Hungary, 26-30 August 2002
- I suggested to one of my master students a study for resonance matter.
We obtained the effective mass spectrum for Au-Au collisions. We observed
some peaks (more or less significant) for rest mass around 300 MeV, 700 Mev,
1200 MeV. Now we try to make a background and to establish a few
characteristics. We hope to have some results in a few weeks
- Because the experimental pionic and kaonic temperatures are enough high
we tried to use the "blue shift" and introduce the flow of the nuclear
matter (T = T(freeze-out)+mass.(flow velocity)^2). Interesting dependence
on the collision energy and participant number are obtained (flow
velocity is around 0.590c for Au-Au collisions at sqrt (s)=200 A GeV. We
worked in two modes: fixed freeze-out temperature (140 MeV) and free value
for freeze-out temperature. Some results are included in the work for EPS
conference.
- An other direction was related to the antiproton/proton ratio. I
observed that the product between mass and flow velocity can be related to
the chemical potential. Taking into account the proposal to consider
antiproton to proton ratio proportional with exp (-nucleon chemical
potential/temperature) I observed a very good agreement between our
experimental results and predicted values. I try now, together my
colleagues, to collect experimental results for temperatures and antiproton
to proton ratio from the others collaboration from RHIC-BNL, to verify if
these agreement is preserved.
Johns Hopkins (YKLee)
-------------------
We were studying how the 38 tiles held up during the 2001 run.
The pp-run of January, 2002, afforded data for clear in-beam
calibration of the tiles because of the low charged-particle
multiplicity. The single minimum-ionizing-particle spectrum of
a tile with a vertex cut within 10 cm is shown in
http://pii3.brahms.bnl.gov/~mult/pp-calib-2001/Tile0_MIP.gif
The multiplicity trigger implemented during the 2001-run
was based on outputs of discriminators with common discrimination
level for all tiles. In June 2001 the single MIP response of all
tiles were equalized within +- 5% using cosmic rays calibration.
How did it maintain the calibration through seven months period? See
http://pii3.brahms.bnl.gov/~mult/pp-calib-2001/calib.gif
Clearly the spread of the single MIP heights is increased to
+- 10%, and most of the drift in pulse height is in the direction
of increase.
NYU
-------
Strasbourg
--------------
------------------------------------------------------
Flemming Videbaek
Physics Department
Brookhaven National Laboratory
tlf: 631-344-4106
fax 631-344-1334
e-mail: videbaek@bnl.gov
This archive was generated by hypermail 2b30 : Wed Jun 12 2002 - 20:29:14 EDT
