Hi, After working together with Hiro last week on resolving some final
problems, I think
we have a reasonably good module for obtaining the multiplicity and
multiplicity based
centrality for the si and tile detectors. Both sets of detectors are
now giving consistent
multiplicities and we should now be able to use the multiplicity based
on the sum of the
two measurements. The new modules correct for vertex locations between
-20 and 20 cm.
Also, the modules use the latest "best" energy calibrations for both the
Si and tiles. It should
be noted that significant problems were found with the ealier energy
calibrations of both sets of
detectors.
Because of the reorganization of the mult files in brat, it is not
currently possible to make these
modules available for cvs checkout. Rather, for the moment, if you need
correct multiplicities
or multiplicity derived centralities you will need to copy the mult
routines from the brat directory on the
Kansas account on the piis. The modules are found in
../kansas/Brahms/brat/mult with the calibration
parameters in ../kansas/Brahms/brat/params/mult. The BrAuxMult module
found in the ../brat/mult
directory is an attempt split out methods that are not essential for the
basic analysis. This Aux module
does incorporate JH's centrality calculation to allow comparison with
the newer results. I was hoping to
be able to develop a simple procedure for working with these modules
but, alas, since I have not
yet upgraded to the 2.25 version of root, I'm unable to compile the
latest cvs version of brat...
It should also be noted that some of the calibration parameters will
almost certainly be refined over
the next couple of weeks. It still appears that the newest BB and ZDC
vertices are shifted by a couple
of cm for low multiplicity events. This is based on si and tile energy
measurements as a function of
vertex location. Unfortunately, a shift in the vertex location looks
the same as a slight tilt of a
si or tile detector element. However, the observed shift is very
consistent for both sets of
detectors, suggesting a posible problem with the BB vertex.
Since the energy calibration of both si and tiles depends on
knowing the vertex location, as the position becomes better detemined we
can improve on
our energy calibration.
I see two possibilities for getting these routines (or, more important,
their functionality) into brat:
1.) Christian makes the functionality available within his new
package. Here I only ask that the
methods set up in the RdoMult module be preserved: I have a large
number of support and analysis
programs that have been developed based on the BrRdoModuleMult and
BrRdoMult classes. One
advantage if Christian does the conversion is that, presumably, the
parameters would then
be properly incorporated into the brat database.
2.) Once the current crunch get over, I can work on the merging things
in. However, I may
have trouble finding time to work on this until after the spring term is
completed.
Hiro has been working pretty much outside of the brat framework and
expects to shortly have
some modules that one can use interactively within root. This would be
similar to how
JH's centrality module has been used. He will post these routines as
soon as they are ready. We
will try to keep the parameters in his routines and those in the brat
rdo modules (in th e Kansas
account) as syncronized as possible...
We hope to have revised dn/deta distributions by mid-week. At that
point (or later this week)
we should be able to post more details on the energy calibrations and
other calibrations
that have gone into the new mult and cent determinations.
...steve
This archive was generated by hypermail 2b29 : Mon Feb 12 2001 - 01:21:47 EST