80066622

By: ValentinHirschi <valentin.hirschi@gmail.com>

retain canonical physical threshold centers across stability probes

Prepare the complete accepted-cut overlap structure at the original physical
point and reuse its center authority through native precision and rotations.
Preserve native cut kinematics, selected subspaces and complementary momenta.
Archive focused and broader gates and the all-orientation GL638 reproducer.

Validation: 14 focused and 27 broader test executions passed; cargo check,
formatting and Clippy passed with no changed-line diagnostics. Six retained
physical diagnostic calls pass, including the previously failing CT-on Euler
probe. Canonical data and saved state hashes are unchanged.

User requests:
Continue as planned, but after this current round of optimisation completes for the joint advanced sampling, stop optimizing further; we will accept current advanced sampling performance as-is for now. Instead focus on verifying that the physics expectation are met. That is:

i) The integrand weight in the HZ corner are now bounded.

ii) The variance of at least the absolute value of the integrand, but hopefully also of the integrand itself, is improved. (compare the MC error at a) fixed sample counts without advanced sampling, b) with only combinations of channels with simpler non-joint advanced maps, c) with the full optimal combination involving also joint advanced sampling maps)

iii) For a reasonable number of sample gain confidence of the fact that the case c) above leaves a bounded maximum weight, and at least smaller than the one found in b) and c). Also analyze what is the origin and cause of the remaining max weight point in b) and c) setups.

iv) Provide you current best estimate (central value + error) you current have now on GL638 cross-section. You can use up to 30 cores and 300 GB of RAM; but use less if you don't see performance scale linearly with number of cores until 30.

Continue as planned, but did you already do a local instpect/approach of the HZ corner to establish that the new joint map makes the GL638 weight bounded there now?

(
continue as planned, but also consider different combination of channels which you think are optimal,e.g. something like:

| ChannelTarget | |
| --------------- | ----------------------------------------------- |
| Cut 0 | `cut(2,6,12,13)` |
| **Cut 1 + H/Z** | `cut(2,6,10)` combined with joint H/Z focusing |
| Cut 2 | `cut(2,6,7,13,14)` |
| Cut 3 | `cut(2,4,12)` |
| Cut 4 | `cut(2,4,10,13)` |
| Cut 5 | `cut(2,4,7,14)` |
| Soft coverage | One LMB: `[6,12,13,14]`, containing both gluons |

Although the soft channel may not even be necessary.

Experiment with different combinations.

So toggling on/off the join mapping should not be by itself, but rather always in the presence of cut channels.

but of course also compare against the baseline of just the optimized LMBs (which is what we had before).

)

Timeline