[Halld-cal] [EXTERNAL] Re: BCAL timing in 2017 and 2018

[Sean Dobbs]

Hi all,

We ran out of time at the Calorimetry meeting, but I wanted to bring
this email that I sent last week up again, to see if anyone had any
thoughts (or maybe the issue was resolved offline?).  This seems
crucial for anyone analyzing data.

Cheers,
Sean


On Tue, Jan 14, 2020 at 6:11 PM Sean Dobbs <sdobbs at fsu.edu> wrote:
>
> Hi all,
>
> The discrepancies that Jon Zarling has seen between runs in the
> 30000's and 40000's
> (https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_HDGeant4_issues_138&d=DwIGaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=qOykDDW07dxNIz2gqzRW_0sRJeff1E30DnojDqga1Jo&m=llxvVoZ7wsuecIack2vbuUMu79EpKeVw_gitHamRkIg&s=dDtKWiKdLkksLeY6aigp4uby4-GeM8Q1VXDxNi9PsaE&e= ) were brought up
> in today's HDGeant4 meeting.  Differences between run periods are
> surely due to some difference in the calibration constants used.
>
> I wonder if someone could remind me what the difference between how we
> did timing calibrations in 2017 and 2018 was?  I noticed that
> /BCAL/tdiff_u_d had non-zero values in the 30000's and was zeroed out
> in the 40000's.
> Frankly, I can't remember what was done right now and couldn't find
> out where it was written down.   This is relevant to the simulations
> since this table is applied when calibrating digihits, but isn't
> compensated for in mcsmear.  But maybe I'm not remembering an
> important piece to the puzzle...
>
> Cheers,
> Sean
>
>
> ifarm1402.jlab.org> ccdb cat BCAL/tdiff_u_d:41509:mc | head -n 15
> +------------+
> | tdiff_u_d  |
> | double     |
> +------------+
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> | 0.0        |
> <SNIP>
> ifarm1402.jlab.org> ccdb cat BCAL/tdiff_u_d:31001:mc | head -n 15
> +------------+
> | tdiff_u_d  |
> | double     |
> +------------+
> | 0.3226     |
> | 0.3226     |
> | 0.3226     |
> | 0.3226     |
> | 0.1294     |
> | 0.1294     |
> | 0.1294     |
> | 0.1294     |
> | -0.1444    |
> | -0.1444    |
> | -0.1444    |