Talk:C parity

Conservation of C-eigenvalues and Linear momentum
I would add the fact that c (the eigenvalue, ±1) is a conserved quantity only in decays mediated by interactions with C-symmetry, i.e whose lagrangian is invariant under C, and of course only when the initial and final states are eigenstates of C. In other words, I would add that weak interactions are not C-symmetric and therefore weak decays can take place between eigenstates of C with different eigenvalues. The conservation of C in decays, that for example makes "impossible" a decay of J/Psi onto two photons, is only there when such decays are electromagnetic or strong-mediated ones. Also, some information of G-parity (see http://pdg.lbl.gov/2014/reviews/rpp2014-rev-quark-model.pdf).

As for the linear momentum, it seems a bit strange to say that C-parity leaves linear momentum unchanged. I would just say momentum, because linear momentum is the first term of the power series of momentum. However, I would like to read some thoughts about this before changing anything because being just an amateur physicist I don't trust myself that much.

Two Boson bound state
The result on the c-parity eigenvalue for a pair of bounded bosons holds only for the pion case, because it has spin zero. See for example "Introduction to elementary particle physics" by Alessandro Bettini, Cambridge Press, pag. 89. Luigi Pertoldi (talk) 19:54, 23 June 2016 (UTC)