12
ψ
±
=
N
±
[
ψ
A
(
1
)
ψ
B
(
2
)
±
ψ
A
(
2
)
ψ
B
(
1
)
]
ψ
±
=
N
±
[
ψ
A
(
1
)
ψ
B
(
2
)
±
ψ
A
(
2
)
ψ
B
(
1
)
]