fraction of the total LHC cross section comes from gluon-gluon and given that conservation of momentum would require co-planarity in the HPF of the outgoing partonic momenta in any $2\rightarrow 2$ or $2\rightarrow 3$ parton-level process, one might be concerned that $\alpha$ appears to lack sensitivity to parity-violating effects in some important places!

Such concern is, however, premature. The *only* way in which a set of co-planar momenta can have a notion of handedness akin to parity is if the plane in which they live is orientable.[^7] It is for the same reason that the (planar) letter **R** can be distinguished from its mirror image only if *one* side of the paper on which both are printed is deemed ‘special’. The plane separating two *identical* interacting initial-state partons in the HPF is necessarily *non*-orientable.[^8] Therefore, although $2\rightarrow 2$ and $2\rightarrow 3$ processes using gluon-gluon and quark-quark initial states are those in which one might have feared the aforementioned ‘wash out’, these same initial states are necessarily those which can carry through no notion of handedness from the intial to the final state in the HPF anyway, let alone one that could be washed away by symmetric boosts from that frame 