Spin of 1p1n Nuclei: Theory & Explanation

[zhangguoqiang]

I am interested in the topic of the thread
https://www.physicsforums.com/showthread.php?t=768539
,especially for those unpair 1p1n case.

As I know, for the simplest case deuteron, the J^π (groundstate here and later) is 1⁺ but 0⁺.
This is very different to the atomic physics case. For He atom, 2 electron create the ¹S₀ groundstate.
For ¹⁸F, it is again 1⁺, although n and p are in the same orbital d_5/2, which can combine the possible 0⁺,1⁺,2⁺,3⁺,4⁺,5⁺.
For ⁵⁰V is 6⁺.

Could someone help to explain? Is there theory for the 1p1n structure?

 

[Vanadium 50]

Yes. The nuclear force is spin-dependent, so for the deuteron, the spin-1 state is lower than the spin-0 (which isn't even bound).

 

[zhangguoqiang]

Thanks, for 18F, is the same reason?