[Halld-cal] Fwd: BCAL in the new year / brainstorm

[Elton Smith]

Hi all,

I have created four slides with the information on the bullets that we 
discussed last Thursday. They are uploaded as GlueX-doc-2900. I have not 
yet added the times estimates requested for running (see page 4), 
although Will has updated his slides in the logbook 
https://logbooks.jlab.org/files/2016/01/3370103/fall2015_pi0_firstlook_1.pdf 
with times estimates for the running. Comments/suggestions/feedback on 
slides are welcome.

Will:
pi0: Could you estimate the amount of statistics (number of pi0s with 
some assumption for the signal/background) that is need in a single 
histogram (i.e. configuration) in order to calibrate that data with the 
pi0 minimization? We can then take the number of configurations we want 
to use (e.g. number of bins in angle, i.e. bins in the coordinate along 
z) and multiply by this number to determine the total required running time.

etas: Do you have enough data to estimate how large a sample is required 
to do a calibration with etas?

Everyone:
- Any estimates for the production (xdecay br) of omegas? (I will ask 
Simon if he has some estimates).

Thanks, Elton.



Elton Smith
Jefferson Lab MS 12H3
12000 Jefferson Ave STE 4
Newport News, VA 23606
(757)269-7625
(757)269-6331 fax

On 1/7/16 10:57 AM, Elton Smith wrote:
>
> Hi all,
>
> At the Spring 16 preparation meeting next week, we are asked to report
> next week on BCAL
> - achievements and problems during fall 2015 run
> - preparations needed for spring 2016 run
> - goals for the Spring 2016 run
>
> Thoughts/comments on the fall run
> - One discriminator was bad and has been replaced. (Need to verify
> operation now)
> - Environmental monitoring is working well now. We operated at 10 deg C,
> but should consider running lower, e.g. chiller at 5 deg C
> - The NSB,NSA values were reduced to 0,26. See Log Entry
> https://logbooks.jlab.org/entry/3368391. This resulted in a pi0 peak at
> about 109.
> -- The pi0 peak is probably directly affected by the pulse integral, but
> also by assuming the position of the target is at the center of the
> hydrogen cell. The solid target was located downstream at the exit of
> the start counter. This may also affect the peak position.
> -- It would be nice to confirm that we understand the current
> normalization, i.e. obtain the correct pi0 peak using the correct target
> information.
> -- The BCAL pluggins run offline show fairly nice peaks for the pi0, but
> they don't have fits, so I don't know how the actual resolution compares
> to our previous data.
>
> Items that should be worked on before the next run starts:
> - We should check that runs with multiple triggers are correctly
> identified. (We had runs this way last spring, but the trigger
> information was not being passed on to the analysis. David was working
> on this and probably has made the information available, but this needs
> to be checked).
> - We should also check the inclusion of LED pulser data into production
> running. This can be checked before the run starts with cosmic data.
> - The software to check the functioning of all the SiPMs before the run
> starts only works with the stand-alone DAQs. We need to rewrite the code
> to accommodate data taken with the TS.
>
> Goals for the next run:
> - Systematic studies of resolution: dependence of pi0 resolution and
> peak position on z-position of showers, energy and angle dependence of
> resolution,
> - Study eta peak and compare with expectations
>
> Ongoing projects:
> - Comparison of MC with data. Adjust MC so that it matches the data and
> can be used with confidence for various systematic studies.
> - The cluster finding / shower reconstruction needs to be optimized.
> - Michel electrons, understanding threshold effects in BCAL.
> - Complete set of calibration constants for BCAL, including time-walk
> corrections. Check timing of TDCs, look at time-of-flight.
> - Understand the efficiency, differences between mode 8 and mode 7 
> running.
>
> We can discuss some of these questions tomorrow at the reconstruction
> meeting.
>