[Brahms-dev-l] Re: cucu "bad" runs

Hi,

if I have 0 matched FFS tracks in an event, how to I correct the 0 tracks
with an efficieny that depend on X and slope in X? I could efficiency
correct the results if the efficiency is only a function of some global
parameter. (I dont think there is a simple correlation, on event
by event basis when you select a track trigger, between the occupancy of the
TPCs and the centrality of the collision. ie a peripheral collision could
easily have a high occupancy in the TPC when you select track triggers...)

Anyhow I does not matter how you do it. You only have X number of tracks,
which gives you your statistical error, no matter what way you wish to add
coorections; acceptance or efficiency.

I do not throw away any tracks. Ther region in T1 which is not working
does not have any (extremely few) local tracks, and so you dont get any
matched tracks either, so the specialized accmap just reflects the
geometrical acceptance of the FFS with the middle part of T1 out of
order, ie you can only see particles in a smaller pseudorapidity bin.

I dont need to redo the gtrs since they do miss any information that I
need, I do not use the BFS.

Could you add text to your plots explaning what they show, I dont
understand all of them....

Cheers,
	Truls

*---------------------------------*
|http://www.nbi.dk/~trulsml      /
|Truls Martin Larsen            /
|trulsml@nbi.dk                .
|The Niels Bohr Institute     //
|Work Address:               / \0
|Blegdamsvej 17             /\_/
|DK-2100 Copenhagen        /  /
|Tel: +45 35325269        / --
|                        /_/  |
|Home address:          /     \
|Holger Danskes Vej 28H|      '
|DK-2000 Frederiksberg |
|Denmark               |
|Mob: +45 20974802     |
*----------------------*

On Mon, 25 Jul 2005, Pawel Staszel wrote:

> Hello Truls,
> I've plotted T1 efficiency  for "bad" runs in cucu63 data:
> http://zefir.if.uj.edu.pl/staszel/brahms/fseffic/cucu63_t1/index.html,
> other detectors look very nice.
> I don't claim that what your are doing is not correct but certainly
> using normal acceptance and just correcting for T1 efficiency is also
> a nice option. I think that you would minimize the losses in statistics
> that way,
>  because you don't discard any track. In momentum you end up with
> relatively smooth
> modulation.
>
> By the way, I checked that the latest cucu63 gtr data  have been generated
> on May. Is it because you wait for new multiplicity calibration from Steve?
>
> Cheers,
> Pawel.
>
> --
>  ----------------------------------------------------------------------
> | Pawel Staszel                                                        |
> | Jagiellonian University                                              |
> | Institute of Physics            email:      ufstasze@if.uj.edu.pl    |
> | Reymonta 4                      phone:      (+48) 12 663 5712        |
> | Krakow 30059                    FAX:        (+48) 12 633 7086        |
> | Poland                                                               |
>  ----------------------------------------------------------------------
>
>
>

_______________________________________________
Brahms-dev-l mailing list
Brahms-dev-l@lists.bnl.gov
http://lists.bnl.gov/mailman/listinfo/brahms-dev-l