Re: [Brahms-l] Npart and Ncoll calculator - now with errors...

Dear Steve,
I'm trying to plot the systematic error band on the plot showing forward 
Raa versus N_part (AuAu_at_200 run04).

What I need is an error on Ncoll. In the Radeks macro I see   
886.8+-39.3 for centrality 0-10%  and
534.3+- 45.8 for centrality 10-20%. Now, using your calculator for the 
same centrality classes I got
the same n_coll but quite different errors, namely 10.1 for 0-10% and 
21.3 for 10-20%. Probably Radek was using
previous version of the calculator.
Could you comment on this?
Thanks,
Pawel.

Stephen Sanders wrote:

> Hi,   I have updated the Npart and Ncoll calculator at
> http://kunuc10.phsx.ku.edu/~sanders/cent2npart.html
> to include the calculations needed to deduce Glauber model
> uncertainties.  At the moment the calculations are done for 62.4 and  
> 200 GeV AuAu.
> The new results are reasonable consistent with the latest draft of  
> the 62.4 GeV paper,
> although the quoted 0-10% Ncoll uncertainty may be a little low.
>
> I tried to include enough detail on the page to make clear what was  
> done.  If not, let
> me know and I'll try to clarify.   Each of the RHIC experiments seems  
> to be making its own
> assumptions as to the Glauber model parameters and their  
> uncertainties.  I've taken something of
> a composite approach.  Several references are given with the  
> calculation results.
>
> Following up on a question JH posed at last Thursday's meeting, the  
> calculator also includes a Ncoll(central)/Ncoll(peripheral)  
> option.     This allows us to explore the
> uncertainties on this ratio.   Unfortunately, the uncertainty on the  
> total multiplicity yield is one of the
> larger error terms.  This term does not tend to cancel out in taking  
> the ratio.
>
> Comments, suggestions and questions are welcomed...
>
> ...steve
> _______________________________________________
> Brahms-l mailing list
> Brahms-l_at_lists.bnl.gov
> http://lists.bnl.gov/mailman/listinfo/brahms-l
>

-- 
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| Pawel Staszel                                                        |
| Jagiellonian University                                              |
| Institute of Physics            email:      ufstasze_at_if.uj.edu.pl    |
| Reymonta 4                      phone:      (+48) 12 663 5705        |
| Krakow 30059                    FAX:        (+48) 12 633 7086        |
| Poland                                                               |
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