Wednesday, July 20, 2016

CPT symmetry as it applies to matter/antimatter


I've heard/read a couple different definitions for antimatter: it is charge-reversed matter (typical definition, for the lay person at least), or it's time-reversed matter (as described in QED).


Then there's CPT symmetry, which means that a universe with all charge and time direction reversed, and mirror imaged spatially, should evolve according to the same laws as our universe.



OK, my question(s). If, in our universe, you were able to take an electron and reverse its charge, parity, and time direction, is that CPT-reversed particle identical to the original electron? So for example, would it annihilate if it came into contact with an electron, or would the two interact just like two regular electrons?


Another way to phrase this is to ask, if antimatter is charge-reversed or it's time-reversed, if you take matter and both charge- and time-reverse it, is it back to the original state? And does P play any role here (could you also describe antimatter as parity-reversed matter)?


Aside from oversimplifying, I may be mixing two different concepts together here (confusing "follows the same laws" with "is the same thing", roughly speaking). Thanks in advance for any answers or clarifications!




No comments:

Post a Comment

classical mechanics - Moment of a force about a given axis (Torque) - Scalar or vectorial?

I am studying Statics and saw that: The moment of a force about a given axis (or Torque) is defined by the equation: $M_X = (\vec r \times \...