RE: Vertex determination

From: Ian Bearden (bearden@nbi.dk)
Date: Mon Aug 20 2001 - 11:44:06 EDT

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    > -----Original Message-----
    > From: owner-brahms-dev-l@bnl.gov [mailto:owner-brahms-dev-l@bnl.gov]On
    > Behalf Of Trine Tveter
    > Sent: Monday, August 20, 2001 4:41 PM
    > To: brahms-dev-l@bnl.gov
    > Cc: trine@lynx.uio.no
    > Subject: Re: Vertex determination
    >
    >
    > Hi Ian, Claus and others,
    >
    > We've looked very briefly and qualitatively at vertex correlations
    > here in Oslo too, and we see nice correlations between BB and ZDC and
    > between BB / ZDC and track intersections with the beam plane (much like
    > Claus' plots) - there's only the question of an offset.  From run 3969,
    > I very roughly determined "by hand":
    > bbpos = bbpos(raw) - 9 cm (approximately)
    > zdcpos = zdcpos(raw) - 42 cm (very inaccurate)
    > where the "raw" values are the ones delivered by BrBbRdoModule and
    > BrZdcRdoModule.
    We see similar values, but the width of the difference (BB-ZDC) is very
    broad.
    Perhaps this is because we use a version of BRAT which does not include some
    secret ZDC calibration...
    >
    > Ian wrote:
    >
    > > Is there a module which takes local TPM1 tracks and returns Z?
    > Is there
    > > another way one can do this? Say, any module which takes TPM1 data and
    > > returns Z?  And can this be used in the context of Christian's
    > bratmain.
    > > Rumors from the north (of Copenhagen!) indicate something in the works,
    > > but I could not find anything in the html documentation on pii3.
    >
    > We're working on translating the BrTPMClusterVertexModule and
    > BrTPMTrackVertexModule to the Brat2 TPC class standard - our eminent
    > vertex expert Bjørn is unable to work full time on this right now,
    > but Truls, Bjørn and I will try to come up with something within the
    > next 1 - 2 weeks.
    That sounds good, except for the time scale.  I had hoped for 1-2 hours :-)
    I suppose that once Djamel calibrates the BB, I'll take that to be the
    'official'
    vertex, and be happy.
    Thanks for the update!
    -Ian
    >
    >                                           Best wishes,
    >                                              Trine
    >
    >
    



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