@ecterrab: Thanks for your answer.
For working with the Standard Model and related, not least with the Dirac-, Weyl-, and Majorana Lagrangians, I use procedures and functions of my own pedigree. From the Physics package, I use only its ability to work with anticommuting numbers, i.e., Grassmann numbers; this feature is highly appreciated, though. Several times I have contemplated migrating these functionalities of mine to the realm of the Physics package, but every time these attempts have failed because I hit seemingly roadblocks, or simply get frustrated over what appears to me to be non-intuitive formalism.
Let me illustrate it with a simple thing: the mass term of the Dirac Lagrangian: Entering it as
Setup(anticommutativeprefix = psi):
Dagger(psi) . Dgamma[~0] . psi;
makes no sense, as psi is moved to the left of Dgamma[~0]; understandably so, I guess, as psi is not specified as a column vector, although specifying it as such while keeping Dgamma[~0], produces a result no more useful. Then we can try something like the following:
anticommutativeprefix = psi,
Dgammarepresentation = chiral
spinor := Vector(4,symbol = 'psi');
Dagger(spinor) . rhs(Dgamma[~0][matrix]) . spinor;
This, at least, produces a sensible mass term, but only at the expense of the 'unnatural' construction rhs(Dgamma[~0][matrix]).
Perhaps I am missing something? Perhaps issues like this are not present in the Standard Model package of Physics under way?