Hi Fouad The problem to me is if the scaled rapidity means anything. I'm not convinced that it does and therefore to me it is more natural to use rapidity. For p+p we know that the probability to loose delta-y is roughly P(delta-y) ~ N*exp(-delta-y) (corresponding to dN/dx_F beeing flat) at all (large) CM-energies, so there you have <dy> ~ 1.0 People have tried to generalize this in for example the multi-chain-model, by folding many proton rapidity loss distributions with some parameter to simulate that the 2nd collision and so forth is off-shell, and there you do have a saturation of the rapidiity loss <dy>. I think your point is very good and this should be discussed at the collaboration meeting. Cheers Peter On Wed, 3 Dec 2003, Fouad Rami wrote: > > > Hi Peter, > > The draft looks very good. Very nice results. > > I have a few comments/suggestions: > > - I suggest to plot Fig.3 as a function of the scaled > rapidity (Ycm/Ybeam). This is the most natural way to compare > data at different energies. One should remove trivial energy > dependences. > Another advantage -> we don't need to show the 3 vertical lines > (Y_AGS, Y_SPS and Y_RHIC). > And this would make the discussion much simpler... > > - The last sentence of the paper says "... the rapidity loss seems to > saturate between SPS and RHIC energies" > It seems to me that this saturation does not mean anything. > Actually, in order to compare different energies one should define > the rapidity loss as (yp - <y>)/yp (as in Ref.3). This quantity would > be constant (=0.64) from AGS to SPS and would deviate significantly > from the scaling at RHIC. The value of the (scaled) rapidity loss > at RHIC would be much lower than at AGS/SPS which would reflect > simply the fact that the collision is much more transparent at RHIC. > All this discussion would become much more simpler, if you use > the 'appropriate' definition of the rapidity loss (yp - <y>)/yp) > in Fig.4. > > Best regards, Fouad > > ----------------------------------------------------------------------- > Fouad RAMI e-mail: fouad.rami@ires.in2p3.fr > IReS phone : 33.(0)3.88.10.62.00 > 23,rue du Loess : 33.(0)3.88.10.64.55 > B.P.28-BAT.20 (secretary's office) > 67037 Strasbourg Cedex 2 fax : 33.(0)3.88.10.66.14 > France > ----------------------------------------------------------------------- > > > > > On Tue, 2 Dec 2003, Peter H. L. Christiansen wrote: > > > Hi > > > > > 13:45 > > > Publications > > > Status & outstanding issues of papers to be presented by paper committee. > > > > > > ( JH d-Au dN/deta paper (SJSanders) (10) > > > Stopping paper (IG.Bearden) (20) > > > Kaon an pion (meson) paper (D.Roehrich) (20) > > > Centrality dependence of charged hadrons at y~0 and 1 (JH.Lee) (20) > > > > > > > You can look at the current status of the stopping paper in our paper cvs > > or check it out here. : > > http://www.nbi.dk/~pchristi/stopping.ps > > http://www.nbi.dk/~pchristi/stopping.pdf > > > > I hope there will be a good discussion about it at the collaboration > > meeting, so we can submit it around the 15th of December. I am not > > interested in comments about details and the language from everybody now. > > If the plots and content, i.e, the general layout that has been accepted > > by the paper commitee is agreed upon at the meeting then I think we can > > fix the rest quickly. > > > > Cheers > > Peter > > > > > > > > > > _______________________________________________ > > Brahms-l mailing list > > Brahms-l@lists.bnl.gov > > http://lists.bnl.gov/mailman/listinfo/brahms-l > > > > -- :-) --------------------------- )-: Peter H L Christiansen @ NBI EMAIL : pchristi@nbi.dk OFFICE : Tb1@NBI (353 25269) HOME : Frimestervej 22, 1. tv PHONE : 35824930/40840492 :-D --------------------------- \-: _______________________________________________ Brahms-l mailing list Brahms-l@lists.bnl.gov http://lists.bnl.gov/mailman/listinfo/brahms-lReceived on Wed Dec 3 05:26:11 2003
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