Hei Michael and Bjorn, Gunter Roland integrated our (NA49) momentum spectra Nucl.Phys.A661:45-54,1999 and showed the dn/deta/nn-pairs in the PHOBOS publication Phys.Rev.Lett.85:3100-3104,2000: dn/deta = 1.9 * 362/2 = 344 (5% cent. Pb+Pb, 158 AGeV) With best wishes, Dieter ------------------------------------------------------------------- Dieter Roehrich | Fysisk institutt | Email: Dieter.Rohrich@fi.uib.no Universitetet i Bergen | Tel: +47-555-82722 Allegt. 55 | Fax: +47-555-89440 N-5007 Bergen, Norway | WWW: http://www.fi.uib.no/php/drhrich.html On Mon, 3 Dec 2001, Michael Murray wrote: > 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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