Re: Important vtx-update! PLEASE READ!

From: Bjorn H Samset (bjornhs@rcf.rhic.bnl.gov)
Date: Wed Nov 08 2000 - 09:36:40 EST

  • Next message: I. G. Bearden: "Re: Important vtx-update! PLEASE READ!"

    > The checking that we have done indicates that while the cluster vertex
    indeed
    > finds many more vertices than the track vertex ( I guess this is what
    > you mean by
    > 'efficient'), 
    
    Yes - what I meant was loosely that it finds more vertices over a wider
    z-interval plus shows a narrower correlation with BB - see below.
    
    >in something like 25% of events (at least for run2535)
    > the cluster vertex Z
    > is not correlated with the BB Z.  I think that this means that you
    > should not only check that
    > the vertex is found, but also should check that, say, BB and Cluster
    > (or track, or whatever) are consistent. 
    
    Indeed - this is on the "to-do"-list. The reason why it is not included
    yet is 1) that I do not know what consistency we should demand. I would be
    very glad if you have done some work on this :-) and 2) that I am working
    on figuring out what goes wrong in these 25% of the events... This is way
    to much to be random errors (I think), so it looks like the thing just
    sometimes picks the wrong peak. Analysis of this is underways. I hope that
    I will at least be able to tell _when_ something goes wrong so that the
    "background" in the corr. with BB will go away.
    
    Ping :-)
    
    ------------------------------------------------
    Bjorn H. Samset
    Master-student in Heavy Ion physics
    Mob: +47 92 05 19 98  Office: +47 22 85 77 62  
    Adr: Kri 2A709 Sognsveien 218 0864 Oslo
    



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