Physics Department,
University of California,
One Shields Avenue,
Davis, CA 95616
Versions of the Paper
Yes, truly, at long last, here is the pion spectra paper, which is
intended for Phys. Rev. C.
DRAFT 1 (ps) (15-March-2002) DRAFT 1 (pdf) (15-March-2002)
This is the first version of the paper sent to the collaboration.
The first round brought only one significant set of comments from Chris
Pinkenburg. Here is a link to the text of his
email. Interspersed are some of our responses.
So what's new in Draft 2?
The introduction has been totally re-written. Daniel deserves most of
the credit for what is in there now.
Instead of using the Gazdicki model of entropy production, we have
gone to the simpler approach of mean pion multiplcity per participant so
that we can directly compare with the most recent NA49 results
(nucl-ex/0205002).
We have unified our RQMD simulations: everything shown in the papaer
comes from simulations for b $lt 3 fm. (Previously, we were hungry for
statistics so we used a mixed set of b $lt 5 fm and b $lt 3 fm simulations
which made the paper confusing. Everything should now be consistent.
We got two sets of comments on draft 2: from Chris Pinkenburg and from Paul Chung.
The comments from Chris were mostly minor and are available here.
We added axis labels to the RQMD lastcl plots and corrected a binning error. I
looked into the pi-plus with lastcl of "kaon" and these seem to come from K0*
decays in RQMD.
Paul's comments referred to our efficiency corrections. From discussions with Paul
offline, it became clear that we are using a fract cut in trackdbg and Paul is using
geantdbg. Using geantdbg allows one to ask what is one's efficiency for finding
the best track. Using trackdbg probes the question of what is the
efficiency of track reconstruction. These are two very different
questions.
In order to study inclusive spectra in the manner that we employ, it is
necessary to use the trackdbg strcutures - otherwise we would not get the
correct efficiencies for our analysis. This should be evident.
We were asked to justify our selection of 70% for
fract and cautioned that we might be vulnerable to the extreme
inefficiencies in the forward hole. When Paul originally raised this
point it did cause us some concern, as we had optimized the fract cut at 70% using
mid-rapidity data. We have investigated the efficiency of our cut as a function of
rapidity and have found that this cut is equally effective at all rapidities.
Although we seldom consider having a fixed target experiment to be an
advantage, our ability to study both the forward and backward rapidity
regions independently gives us a powerful cross check on our methodology.
We have examined the forward/backward ratio of our spectra and we find no
evidence to suggest that we have systematically under- or over-estimated
our efficiency in either the forward or backward regions.
Nuclear Physics Group
