| − | where ''a=1'' and ''b=2'', referring to the daughter number. Because an even-symmetric angular wave function (i.e. L=0,2...) imply that 180 degree rotation is equivalent to reversal of daughter identities, ''a,b'' becoming ''b,a'' on must write down the symmetrized expression: | + | where ''a=1'' and ''b=2'', referring to the daughter number. Because an even-symmetric angular wave function (i.e. ''L=0,2...'') imply that 180 degree rotation is equivalent to reversal of daughter identities, ''a,b'' becoming ''b,a'' on must write down the symmetrized expression: |