Hi Michael, Thanks for the plot. Claus and I brain stormed a bit his afternoon, prior to ypour message. ¨ We fit the Brahms data at 200 and 130, the Na49 and the AGS data nicely with a functional: k-/k+= A (pbar/p)** B +C. This suggest a universal scaling of Kaon rations (hence mu_s) with P ratios (hence mu_B). I don't understand your comment about Beccatini being wrong. He has used full rapidity integrated info. Is Becattini wrong or is our plot wrong? Is the issue that in becattini's table different strange fugacities are used (gamma_s)? Our curve uses his values but with gamma_s =1 (i.e. no strangeness loss from the volume). We'll add a mu_b scale on the plot (fig.4) based on pbar/p=exp(-2mu_B/T). Could you send us the numbers and the best ref. for (our) NA44 data at SPS? We would appreciate if you could supply us with the absolute latest AMPT ratios, in a form ready to plug into a root macro. We should really announce this paper at the end of the week. There was significant interest for our data at the Gordon conf. cheers JJ ____________________________________________________________ Jens Jørgen Gaardhøje, Assoc. Prof., Dr. Sc. Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark. Tlf: (+45) 35 32 53 09, secr. (+45) 35 32 52 09, Fax: (+45) 35 32 50 16. UNESCO Natl. Comm., secr. (+45) 33 92 52 16. Email: gardhoje@nbi.dk. ____________________________________________________________ ----- Original Message ----- From: "Michael Murray" <murray@cyclotronmail.tamu.edu> To: <brahms-l@bnl.gov> Sent: Tuesday, June 25, 2002 8:57 PM Subject: Re: Ratios Paper - Draft 2.2 > Dear Claus and Jens Jorgen, > thanks for the new ratios draft. I think > that it is a great improvement. However I have some concerns > about Fig 4, I have attached my version. > The first is that the thermal curve for Becattini is wrong. > >From PRC64 024901 one gets k+/k-=1.17 for pbar/p =0.4. > That gives k-/k+=0.85 at pbar/p=0.4 in good aggreement with our > data. This is the dashed line in my plot. > > Secondly I think it is crucial that we address the question of > weather we have local > strangeness neutrallity at different rapidities. If this were > so as long as the temperature does vary mu_s (and hence k-/k+) > is fixed for a given mu_b (ie pbar/p). Therefore we should > see a universal curve of k-/k+ versus pbar/p. In my plots I have > shown our 130GeV data and pp data from (Alper et al). They > are both in good agggreement with our 200GeV data. > > Third all k-/k+ data lie above (pbar/p)**1/3. Thus we have > a positive mu_s which approches 0 as pbar/p goes to 1. > > Finally I would prefer to use the published NA44 pbar/p ratios > rather than the QM99 pbar/p values from NA49. The spokesman of > NA49 told me that he thought the pbar yields should go down. > This would bring there pbar/p closer to ours. Both experiments > aggree on k-/k+. > > AMPT does not reproduce the data, both k-/k+ and pbar/p are > too high. In my plots the yellow band shows AMPT for the same > rapidity region as our data. Also the Pt slopes are not quite > the same were as for us our ratios have no Pt dependence. > > Masashi has found that feed-down from weak decays does not > effect the k-/k+ or pbar/p ratios very much. This strengens > our case for using them in a thermal analysis. > > For my plot I guess errors of 10% for the pp data. Tess is typing > in the spectra for me so that I can get the proper errors. > The k-/k+ ratio E866 is at y=0 and would be somewhat lower if > averaged over the same region as the pbars, ie 1.0<y<2.2. > > > In summary it seems that a thermal description of our data > with T~160-170MeV and local strangeness neutrallity gives > a good description of our data. K-/k+ vs pbar/p looks like > a universal curve. > > Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899 ---------------------------------------------------------------------------- ----
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