Hei Claus, very interesting data! a few comments: On Fri, 5 Jul 2002, Claus O. E. Jorgensen wrote: > > - (h++h-)/2 pt spectra for 0-5, 5-10, 10-20 and ~40-60% centrality at > eta=0. I guess we also have identified pions (up to pt=2???). We could have a comparison between charged hadrons and pions. > > - pt ratio (R) of central (0-10) to semi-peripheral (~40-60). Here I > conlude that we our measurements indicate a suppression of high pt > particles when comparing central to semi-peripheral collisions - this > comparison is of course independent on fit ranges and reference data > taken with another experiment. is this shown on the your second figure? Then I do not understand the last plot (R vs pt ofr 40-60%). > > - ratios of spectra to p+pbar reference (ua1) data. These ratios are > dependent on the choice of reference data and fit ranges/methods. > However, suppression of high pt hadrons is observed and it is more > pronounced for the central collisions. Here we should follow the PHENIX and STAR method: use R_AA (and the pp parametrization) as defined in http://www.phenix.bnl.gov/phenix/WWW/info/physpub/003/prl/PRL88_022301.pdf or http://www.star.bnl.gov/STAR/sds_l/papers/journals/p2002/highpt.pdf > > - ratios of protons to all hadrons as function of pt. Mesonic vs. baryonic > jets??? Who knows about this stuff? Is my result reasonalbe (I just > pulled out the numbers)? That's nice. Can you plot protons over mesons (all-protons)? look at http://arXiv.org/PS_cache/hep-ph/pdf/0108/0108045.pdf > > - pi- spectrum at y approx 2.2 for 0-15% central. The statistics are > unfortunately not good enough to make qualitative statements on the > slope at high pt. > As Ian suggested, you can chose a coarser binning for high pt. There is no slope at high pt, the spectrum should follow a power law - and it does. > - pi- pt ratios of central (0-10) to semi-peripheral (~40-60). The ratio > constant (within the erros). What do we expect at forward rapidities? What puzzles me is that the ratio is flat at low pt. At high pt we might expect a flat ratio (or even increasing) due to an interplay between initital multiple scattering (Cronin) and/or jet quenching and/or whatever. With best wishes, Dieter
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