Iss1181 - Hcal position reconstruction + geometry verifier

[EinarElen]

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

What are the issues that this addresses?

This resolves #1181 and patches one part of #1166 (missing case statement in getScintillatorOrientation.

This updates the hcal geometry condition so that the map of strip centers aligns with the GDML. I will say that there almost certainly are more elegant expressions than what I ended up using, so if anyone has a suggestion then feel more than free to suggest them.

One thing which caused me quite a lot of headache before I caught it was that the entire Hcal geometry is offset by 19.05 mm in y. I'm not entirely sure why this is, but I've added a configuration parameter that handles this.

Since this was quite fiddly, I wanted to make sure we really got this right so I also added an analyzer in the DQM module which goes through all simulated and reconstructed hits in the hcal and checks if the position is within the bounding box of the corresponding scintillator bar. For the v14 geometry this is 100% correct, excluding reco issues in #1348.

I have not gone through a similar exercise for v12.

Check List

• I successfully compiled ldmx-sw with my developments

• I ran my developments and the following shows that they are successful.
  See analyzer above.

• I attached any sub-module related changes to this PR.
  N/A

Related Sub-Module PRs

N/A

[EinarElen]

I would expect this to fail some of the validation figures, anything that has to do with Hcal positions are going to change.

[cmantill]

Oh dang - is it because:

• https://github.com/LDMX-Software/ldmx-sw/blob/trunk/Detectors/data/ldmx-det-v14/detector.gdml#L49
• https://github.com/LDMX-Software/ldmx-sw/blob/trunk/Detectors/data/ldmx-det-v14/constants.gdml#L427C44-L427C51
  ?

[tomeichlersmith]

the entire Hcal geometry is offset by 19.05 mm in y

@cmantill is correct - I implemented this offset because the ECal support box is slightly asymmetric in the vertical direction (it has to have a base to rest on but it is open at the top for the layers to be slid in like a filing cabinet). I had to slide the ECal volume up so that the sensitive layers were still centered on the beam and thus I had to do the same for the HCal. I apologize for wasting your time from my lack of documenting this.

I would expect this to fail some of the validation figures, anything that has to do with Hcal positions are going to change.

That makes sense - do you want to include your geometry verifier in the validation histograms? Maybe in the hcal validation sample? If we need to recreate the golden histograms anyways, now is a good time to introduce new ones.

[EinarElen]

That would explain it 😅, I've obviously been staring at the stuff for too long because I completely missed that when looking for offsets in the GDML...

Regarding the verifier, I'm not 100% convinced that it is going to be super useful at the moment but yeah maybe on the hcal one. Ideally, if we didn't have #1348 I think it would be quite nice to have it run with quitting on mismatch, that would catch position reco bugs early but before that has been patched that's not an option.

[EinarElen]

All the failing tests are HcalDQM tests related to the side Hcal :)

[tomeichlersmith]

Looks good and code is understandable. I'm approving this since I think it is ready to be merged in. If you want to add the geo verifier to the CI now on this branch, I'm happy to re-review. But we can also wait to pull that verifier into the CI until the HCal reco bug you mentioned is resolved.

[EinarElen]

I also think we can merge it. We can return to the CI question later if we want.