[Halld-tagger] is_fiducial cut in TPOL analysis?

[Justin Stevens]

Hi Richard and Mike,

It is true that there are some analyses which utilize the is_fiducial function of DBeamCurrent to exclude events just before and after beam trips.  This is particularly important if one is interested in rates of hits in detectors per unit time and needs to skip over “beam off” periods.  That said, the ReactionFilter plugin used in our analysis launches, which the majority of collaborators are using for physics analysis, does not require this condition.

So this is not presently the “standard practice” as far as I’m aware, but it would probably be useful to add to your TPOL trees for comparison.

-Justin

> On Apr 3, 2018, at 10:11 AM, Michael Dugger <dugger at jlab.org> wrote:
> 
> 
> Richard,
> 
> We are not using the fiducial cuts due to beam trips. Sounds important to include.
> 
> Thanks for the information. We will have to get that information into the TPOL trees.
> 
> Take care,
> Michael
> 
> On Tue, 3 Apr 2018, Richard Jones wrote:
> 
>> Hello Michael and Sebastian,
>> 
>> A question has come up in discussions here in the counting house, that I
>> thought I would raise with you and Michael. In the physics analyses, the
>> standard practice is to exclude events just before and after beam trips
>> because the properties of the beam can be problematic during those periods.
>> To help with this in JANA, there is a standard object named DBeamCurrent
>> that has a method called is_fidiucial() which returns a true/false value.
>> 
>> Are you using this condition to gate the events you analyze for the TPOL
>> analysis? In order for the polarizations you produce to be directly
>> applicable to physics analyses, both need to select the events under the
>> same beam conditions.
>> 
>> -Richard Jones
>> 
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