# spin parity $J^P$ notation

In particle physics, when you read $J^P$, does it mean Spin parity or total angular momentum parity?

I know that the letter $J$ is used for TOTAL angular momentum but I think I read somewhere that sometimes it is meant spin when used in this $J^P$ notation.

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## 1 Answer

The notation always refers to the total angular momentum. A source of confusion may be that in nuclear physics, we talk about the "spin" of a nucleus as a whole, even though the spin is only partly due to the intrinsic spin 1/2 of the neutrons and protons.

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