Hi JH, thank you for your comments and suggestions. > > According to the published results by us and PHOBOS, > R(eta=0) ~ R(eta=2.2), where > > dN/deta in AuAu for central (0-10% BRAHMS or 0-6% PHOBOS) > R = ------------------------------------------------------- > dN/deta from UA5 > > In Fig. 2, RAuAu(y=0) is ~50% bigger than > RAuAu(eta=2.2) at pt~0.5 GeV/c, near (slightly higher than) > <pt> for pions. Taking into account quoted systematic errors, > the difference is still significant. > I don't think the ratio of [pi-/charged hadron] changes > significantly between eta=0 and 2.2 for the central AuAu > and pp (or pbar-p). If some Jacobian effect is (partly) > responsible for this, we should try to separate trivial > kinematics from dynamics. > This is real good question. I realized it when I was writting my thesis. I couldn't explain why it is that, and also wondered if there is any physics behind it. As you mentioned above you don't think the ratio of pi-/h changes significantly between eta=0 and 2.2 for the central AuAu and pp collisions, but I remember I have calculated the pbar/pi- ratios once for eta=0 and eta=2.2 as shown in the figure 4.25 in my thesis, they are different due to more (anti-)protons has be boosted to higher pt when the collective flow is larger at eta=2.2. However, if calculate the pbar/pi- in rapidity at y=0 and in eta at eta=2.2, we didn't see the big differences by accident. You also mentioned Jacobian effect, but I don't think it is a matter since the Jacobian effect should be cancelled out in Raa calculation. Best regards, Zhongbao _______________________________________________ Brahms-l mailing list Brahms-l@lists.bnl.gov http://lists.bnl.gov/mailman/listinfo/brahms-lReceived on Sun Jul 3 21:31:04 2005
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