Dear Bjorn,
maybe I am misinterpreting the
KLM paper. I looked at the EMU02 paper and they
get dN/deta=400 for the top 4% of centrality.
Yours Michael
Quoting Michael Murray <murray@cyclotronmail.tamu.edu>:
> Dear Bjorn,
> the KLM collaboration has studied PbPb collisions
> at the SPS with Emulsion. They are ref [17] of our 200GeV paper.
> In figure 2 of PRC 62 014903 they plot the multiplicity per
> wounded nucleon W. They have dN/deta/W = .93 at eta=0 and
> in Table 2 list W=2*(170+-7). This gives dN/deta=316+-20 at
> at eta=0 for 10% central PbPb collisions. They say that they
> are consistent with another emulsion experiment EMU02
> PLB 407 92 (1997).
> Yours Michael
>
> Quoting Bjorn H Samset <bjornhs@rcf2.rhic.bnl.gov>:
>
> > 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
> > \|/
> > ----------------------------> -*- <-----------------------------
> > /|\
> >
>
>
>
> Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
>
Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
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