Friends As Claus is away to the Faroe Islands next week, all comments regarding the high pt stuff should come to him ASAP. There will be little time before QM to react after his return. Thanks 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: "Flemming Videbaek" <videbaek@sgs1.hirg.bnl.gov> To: <brahms-l@bnl.gov> Sent: Friday, July 05, 2002 5:29 PM Subject: Re: High Pt analysis > Dear Claus, > > Thanks for the hard work and posting the results, this is precisiely the > kind of data that we I thought we could get out of the long runs at 90 and > 12 deg; > > - since people are getting up in the US you will get another set of comment > suggestions etc. (and more later it is a lab holiday though some folks are > in ) > > My first comments basically do not take into account too much of the other > comments > so there may be some overlap. > > > > > > The main physics plots will be > > > > - (h++h-)/2 pt spectra for 0-5, 5-10, 10-20 and ~40-60% centrality at > > eta=0. > > > Since the 40-60% comes from the non-trigger 6 events and the statistics does > not look too > bad it should be possible to get another bin say from 20-40 to extend the > systematics, in particular > if you make the powerlaw fits showing the n, and pt0 , and the <pt> from the > powerlaw shape. > Since this centrality region overlap with the trigger 6 the scale-down > factors and trigger mix has to be treated correctly. > > > - 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. > > > > - 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. > > > > - 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)? > Did you do 'asymmetric pid at p>3.5 GeV for the protons and the > corresponding increased accpt? > Otherwise I think the p-bar/p are contaminated by kaons. > > > > > - 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. > > I think you should also make the h- spectra at this setting. For pt >=1 the > h- and pi- > can then be compared e.g. looking both directly at the data, and comparing. > This may help us dis-entangle the 'flat' plot of 0-10/(40-60). > Is this due to using identified pions, thus removing the possible fake high > pt- suppression > from the large inverse slope p-bar, and k-. > > The y~2 should be binned in at least 250Mev/C bins, there are too many 1 and > 2 > counts out there. > The overlap between setttings looks good. > Could you also show us the 'raw' 40-60 spectrum . I know the statistics is > not good so > but even merged into the .5 GeV p(t) bins as you do in the final ratio plot > it is useful to judge the > significance (It looks form the ratio and errors that the last 3 bins has 4 > , 2/3 and 1 count respectively). > > > -- Could someone else look into an estimate of Npart/Nbinary for the 40-60 > selection for the way the selection > was done here. I we want to attempt to do the sigma/R(AA) we need such > numbers, and it is a sure question from the > audience. > > Again, thanks for the plots > Flemming > > > > >
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