Missing invariant masses for the kinematics

[Leongrim]

At the moment it seems like the kinematics only creates the invariant masse for subsystems containing resonances because this are the only ones that are needed for the fitting.
For instance J/psi -> KS sigma+ pbar containing N(1650)+ and N(1650)- only subsystems for KS sigma+ and KS pbar are created.
Probably this has to be modified.

[spflueger]

We will have to see who to assign this task to. Any volunteers?

The idea would be to generate all different subsystems using https://docs.python.org/3.7/library/itertools.html#itertools.combinations . Then simply register those Subsystems in the Kinematics instance.

[redeboer]

Any volunteers?

✋ 😒
But probably best to do this together with @Leongrim because he can test it on a use case.

Some useful slides here

[spflueger]

For the record, this is how it was done in ComPWA (c++) https://github.com/ComPWA/ComPWA/blob/master/Physics/HelicityFormalism/HelicityKinematics.cpp#L296