In Lie Algebras in Particle Physics 2ed - From Isospin to Unified Theories (Georgi, 1999) p.283
Georgi wrote:
When we include the $1$ in the $\rm SU(5)$ Unified Theory model, we get the 16 $$ 1 \oplus \bar{5} \oplus 10, $$ which we can restore the Parity $P$ symmetry lost in $\rm SU(5)$ Unified Theory model.
questions
why is the Parity P symmetry lost in $\rm SU(5)$ Unified Theory model? I meant P is lost in weak interactions in general.
why is the Parity P symmetry restored in the 16 as $1 \oplus \bar{5} \oplus 10$?
I am confused.
