[Halld-cal] effective velocity in the BCAL

[gvasil at jlab.org]

Dear colleagues,

I am out of office and I won't be able to participate in our meeting
today.

Kind regards,
George



> Hi folks:
>
> just a brief followup from our discussion on the timing calibration for
> the BCAL.  Andrei is working on producing plots to investigate effects
> that were suggested during our CALWG meeting.
>
> As far as philosophy goes, please glance at the paper from Belle (I
> highlighted a couple of sentences and boxed a table and equation).  Of
> course, this is a collider experiment and they use a TOF system (rather
> than a calorimeter) with chambers, but they do use the same philosophy as
> Andrei in treating v_eff as a parameter.  Their symmetrical situation and
> using muons gives them v_eff numbers for up and down (forward/backward in
> their paper) that are very close, but the point is that they do so to
> optimize timing for their TOF.
>
> Andrei’s presentation and the Belle paper can be found here:
>  http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=3106
> <http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=3106>
>
> As we know, showers are nasty beasts in this regard and give different
> v_eff for different zones, whether layers, cells or up/down ends.  It
> would be great to deconvolute the geometrical effects and come with a
> single v_eff value over the whole calorimeter (as it should be since the
> fibers are similar within ~15%) but this is a daunting task that may
> introduce big errors and degrade the timing resolution.
>
> We plan to discuss all these things and Andrei’s new plots further at
> the upcoming CALWG meeting.
>
> Thanks and cheers, Zisis...
>
> Dr. Zisis Papandreou
> Professor of Physics, Ph.D., P.Phys.
> ---------------------------------------------------------
> Department of Physics
> University of Regina
> 3737 Wascana Parkway
> Regina, SK  S4S 0A2	 CANADA
>
> Phone: (306) 585-5379
> Fax: (306) 585-5659
> Email:  zisis at uregina.ca <mailto:zisis at uregina.ca>
> Website:
> http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html
> <http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html>
>
>
>
>
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