Dear Trine and Dieter,
I think it is worth discussing the
change of shape with centrality even if it only reflects the
growth of hard collisions at central rapidity. What is |eta| RMS for pp and and
what is the reference?
Yours Michael
> and on Thu, 22 Nov 2001, Dieter Rohrich wrote:
>
> > At SPS, the h- rapidity distribution is narrower in central
> > nucleus-nucleus collisions than in nucleon-nucleon. It is not a big
> > effect, but it is significant. I would like to support Chellis'
> > proposal to add a sentence and/or to include the RMS/FWHM in the table
>
> > - if a quantitative analysis (RMS from the histogram, 2-Gaussian fit,
> > etc.) confirms Chellis' observation.
>
> I calculated the RMS values for the dN/dEta distributions
> of various centrality classes for 200 and 130 GeV, from the
> data in the files dndeta_sym_200.dat and dndeta_sym_130.dat
> found at "the usual place at the kansas account".
> The results are plotted as a function of centrality class
> (1 = 0-5%, 6 = 40-50%) in the figures:
>
> http://lynx.uio.no/~trine/brahms/mult/RMS_fullerrors.gif
> (using the full errors taken from the .dat files)
>
> http://lynx.uio.no/~trine/brahms/mult/RMS_smallerrors.gif
> (using the 3% point-to-point errors like in the alpha,beta fits)
>
> Upper panels: Red points 200 GeV data, blue points 130 GeV data.
> Lower panels: RMS 200 GeV / RMS 130 GeV.
>
> The trend pointed out by Chellis looks significant. Also there
> are indications that the width increase from 130 to 200 GeV
> is stronger for the more central collisions (as also seen from
> our figure 4.) What do you think - does this merit a sentence
> in the paper?
>
> The numbers are given below for reference.
>
> Best wishes,
> Trine
> _____________________________________________________________
>
> Full errors:
> 0-5%:
> RMS200: 2.32861+-0.0253931 RMS130: 2.21047+-0.024398
> Ratio: 1.05345+-0.0163451
> 5-10%:
> RMS200: 2.3554+-0.0252404 RMS130: 2.23798+-0.0244402
> Ratio: 1.05247+-0.0161029
> 10-20%:
> RMS200: 2.37433+-0.0252682 RMS130: 2.25484+-0.02383
> Ratio: 1.05299+-0.0157931
> 20-30%:
> RMS200: 2.38742+-0.0255841 RMS130: 2.27923+-0.024796
> Ratio: 1.04747+-0.0159955
> 30-40%:
> RMS200: 2.39571+-0.0255872 RMS130: 2.30663+-0.0247556
> Ratio: 1.03862+-0.0157259
> 40-50%:
> RMS200: 2.40582+-0.025714 RMS130: 2.32596+-0.0251689
> Ratio: 1.03433+-0.0157317
>
> Point-to-point errors of 3% on dN/dEta:
> 0-5%:
> RMS200: 2.32861+-0.00792104 RMS130: 2.21047+-0.00761942
> Ratio: 1.05345+-0.00510162
> 5-10%:
> RMS200: 2.3554+-0.00793332 RMS130: 2.23798+-0.00766753
> Ratio: 1.05247+-0.00505651
> 10-20%:
> RMS200: 2.37433+-0.00796683 RMS130: 2.25484+-0.00771144
> Ratio: 1.05299+-0.00504501
> 20-30%:
> RMS200: 2.38742+-0.00795419 RMS130: 2.27923+-0.00776257
> Ratio: 1.04747+-0.00499057
> 30-40%:
> RMS200: 2.39571+-0.00795148 RMS130: 2.30663+-0.00779476
> Ratio: 1.03862+-0.00491955
> 40-50%:
> RMS200: 2.40582+-0.00793511 RMS130: 2.32596+-0.00777788
> Ratio: 1.03433+-0.00485815
>
Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
This archive was generated by hypermail 2b30 : Mon Nov 26 2001 - 05:05:05 EST
