Optimize ecal biasing factor for 8 GeV

[tvami]

I am updating ldmx-sw, here are the details.

What are the issues that this addresses?

Resolves #1535

Check List

• I successfully compiled ldmx-sw with my developments
• I ran my developments and the following shows that they are successful.

See #1535 (comment)

[tvami]

I'm gonna use this PR to test #1569

[tvami]

/run-validation

[github-actions]

The validation workflow is running here: https://github.com/LDMX-Software/ldmx-sw/actions/runs/13140056694.

[tvami]

I think this works now!

[tvami]

I'll test if it also works in a draft mode

[tvami]

/run-validation

[github-actions]

The validation workflow is running here: https://github.com/LDMX-Software/ldmx-sw/actions/runs/13140159042.

[tvami]

  Switched to a new branch 'iss1535-biasing-factor-optimization'
  branch 'iss1535-biasing-factor-optimization' set up to track 'origin/iss1535-biasing-factor-optimization'.

Yaay it does! Sorry everybody if you got more than than a dozen msg because of this!

[tvami]

I'm opening this for review, as we agreed today that this will not affect anything in the DR and is safe to merge

[tomeichlersmith]

Idk... do we want to wait and see if we are really over-biasing a high energy child-of-primary photon? I'm thinking that maybe there is a bug in our checks on which particles get biased...

[tvami]

this is the Z vertex with a factor of a 1000:

[tvami]

Here is the rest of the KS-failed distributions:
change_bias_factor_1000-ecal_pn_recon_validation_plots.pdf

[bryngemark]

With a factor 1000 it looks like we're getting about 10% more events in the first two bins than we used to (btw is the reference with 8 GeV/550, or 4 GeV/450?). I think this could still mean that we're getting a large enough xsc to trigger a warning but it is suppressed.

Did you get around to running with old_ecal? That should factor the low-Z materials out of the problem. If we can run without these materials, maybe finding the maximum warning-free biasing factor would be a good procedure to optimize without having to look at z.

[tvami]

(btw is the reference with 8 GeV/550, or 4 GeV/450?).

with ref to 8 GeV/550

Did you get around to running with old_ecal?

Not yet, but sounds good

[bryngemark]

I suggest we discuss this at the sw dev meeting today and type up what we learn from that and the email thread with natalia in this issue afterwards.

[tvami]

Let's test with the new gold

[tvami]

[tvami]

So a little bit more interactions in the non-W part of the ecal, but it seems the with a factor of a 1000 it's not too different.

Reminder about the Z dist (now with the clean gold, and normalized plots with error bars):

[tvami]

The rest of the plots that fail the KS (reminder the red is with 550 and the blue is with 1000)
bias-opt-ecal_pn_recon_validation_plots.pdf

[tvami]

Results in https://github.com/LDMX-Software/ldmx-sw/actions/runs/13469761175

The z with using biasing factor of 5000

Material

Volume

So more is happening now in the non-W based elements, I guess this was expected

[tvami]

I'll check now how things look like for biasing factor of 1

[tvami]

I'll check now how things look like for biasing factor of 1

Ohh so with biasing factor of 1 the ecalPN takes longer than 6 hours to run, so github kills it...