On Sat, 1 Dec 2001, Hironori Ito wrote:
> Hello. For appetizer of some people, dndeta for 0-5 % central
> 22 Gev run is about 200 at eta=0 by silicon and tile. A normalization is
> done using Hijing to estimate BB counter (trigger 1) efficiency. (We
> know it is way model dependent.) The number (200) seems to be too
> low. Unless someone comes up with better (or right) normalization, this is
> it for 22 Gev run.
...and TPM1 can (almost)confirm this. Using the same simple normalization
I get
dNdEta ~ 210
at eta=0. However: Comparing the BB multiplicity distribution from geant
with data indicates that assuming a very high efficiency at 0-5% may not
be correct (the nose of the "min"bias is very round), so a better
normalization may well increase this number. (I.e. we need to properly
digitize the BB response - I haven't managed to do this yet.) Also the
vertex distribution I have used in my simulation isn't quite as flat as
the data sample.
On Sun, 2 Dec 2001, Michael Murray wrote:
> Another approach is to calculate the average
> dN/dEta for the 100 highest multplicity events.
> Then you don't have to worry about any efficences.
This (luckily) is easy - for my top 100 events (using BB mult) I get
dNdEta ~ 260
Somewhat higher (I might add that the 0-5% sample above was ~2700 events)
- what dNdEta do we expect for this energy?
I'll hack away at this some more and send more details as I go along.
Ping :-)
--
Bjorn H. Samset Phone: 22856465/92051998
PhD student, heavy ion physics Adr: Schouterrassen 6
Inst. of Physics, University of Oslo 0573 Oslo
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