Ratios from AMPT and pp data

From: Michael Murray (murray@CyclotronMail.tamu.edu)
Date: Tue Jun 25 2002 - 18:30:57 EDT

  • Next message: Michael Murray: "BRAHMS/Ratios/strangeness neutrality"

       Dear Jens Jørgen,
                     attached are the ratios for AMPT vs y and 
    Alper et at  vs sqrt(s). 
                    Michael
    
    
    
    Quoting Jens Jørgen Gaardhøje <gardhoje@nbi.dk>:
    
    > Hi Michael
    > I don't have the copy of Becattini at home. I remember we took the
    > values
    > from a later figure bin the paper, where the strange fugacity is nil.
    > We'll
    > check out tomorrow. Claus actually wrote to Becattini yesterday to hear
    > what
    > he has to say.
    > 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 11:46 PM
    > Subject: Re: Ratios Paper - Draft 2.2
    > 
    > 
    > >    Dear Jens Jorgen,
    > >            thanks for the quick reply. It seems to me that
    > > your plot is wrong. Look at Fig 4 of PRC63 024901. For pbar/p=1
    > > k-/k+ =1 of course. For pbar/p=0.4 k+/k-=1.17 implying k-/k+=0.85
    > > not 0.74 as you show in your plot. I think it is   important to
    > > show our 130GeV data too and so that should be mentioned in the
    > > text. While the errors on NA49's pbar/p are large they are
    > > consistently larger than our results. By the way the AGS data in
    > > my plot are for y=0.
    > >                  Yours Michael
    > > PS I will  send you my ratios in tabul form. However I think that
    > > my plot looks nicer than yours.
    > >
    > >
    > > Quoting Jens Jørgen Gaardhøje <gardhoje@nbi.dk>:
    > >
    > > > 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
    > > >
    > > >
    > >
    > >
    > --------------------------------------------------------------------------
    > --
    > > > ----
    > > >
    > > >
    > > >
    > > >
    > > >
    > >
    > >
    > >
    > > 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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