Lessons from the Light, 5.2

Note that among *C*, *P*, *T*, only *T* is an “antilinear operator” which means that

` T | \lambda \psi \rangle = \lambda* T | \psi \rangle `

including the asterisk which means complex conjugation (that’s the reason of the prefix, anti-). Various combinations of *C*, *P*, *T* are linear or antilinear depending on whether *T* is included.

Note that the complex conjugation is needed for the time reversal already in ordinary non-relativistic quantum mechanics because the complex conjugation is the only sensible way to change (` \exp(+ipx/\hbar) `

) to (` \exp(-ipx/\hbar) `

), i.e. to change the sign of the momentum *p* – and the velocity *v* = *dx*/*dt* – which is needed for particles to evolve backwards.

— BaBar directly measures time reversal violation

— Lubos Motl

2014.06.11 Wednesday ACHK