Hi Brahmers, I've updated my high pt web page (http://www.nbi.dk/~ekman/highpt/highpt.html). It contains more or less what I plan to show at qm. I still need to make the plot nicer to look at, but I think it should be possible to tell a good physics story from these plots. I'm not sure about the pt ratio (0-10)/(40-60) for pions at y=2.2. If I make the plot from the raw pt distributions (directly from the dst) I get the ratio shown on the web-page, but if I do the full analysis with the acceptance corrections I see a very strong decrease from around pt=1.5GeV/c. I suspect it comes from the way the zeros are treated (if one wants to merge 5 bins into 1 bin and 3 of them contains 0+-0, what is the correct way of doing this). Cheers, Claus PS: Flemming, I have a few comments to your comments, see below... PPS: The next week I'll be on the Faroe Island, and my internet acces will probably be limited - but comments or suggestions (that doesn't require many hours of analysis work) are still very welcome. +-------------------------------------------------------------+ | Claus Jørgensen | | Cand. Scient. Phone : (+45) 33 32 49 49 | | Cell : (+45) 27 28 49 49 | | Niels Bohr Institute, Ta-2, Office : (+45) 35 32 53 07 | | Blegdamsvej 17, DK-2100, E-mail : ekman@nbi.dk | | University of Copenhagen Home : www.nbi.dk/~ekman/ | +-------------------------------------------------------------+ On Fri, 5 Jul 2002, Flemming Videbaek wrote: > 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. I wouldn't know how to do this. If one vetos he trigger 6 I guess it bias the data towards more peripheral events - if not, I guess it goes the other way. Is there a clever way around this. > > > - 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. You're right - I' updated this figure and I'm not looking at p>3.5GeV/c. > > > > - 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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