Difference between bound and unbound nuclear states?

Question

What are the differences between bound and unbound nuclear states? What does bound or unbound excited states mean?

Please explain in nuclear sense.

Answer 1

I spent some time searching the term "unbound nucleus", and the first indication was the it meant a continuum in contrast to the bound nuclei in the table of nuclides .

I saw the light in this article ,Nuclear drip line

The nuclear drip line is the boundary delimiting the zone beyond which atomic nuclei decay by the emission of a proton or neutron.

So the boundary, drip line, separates the bound from the unbound nuclides.

It is specialized experiments exploring beyond the table ,

adding nucleons one at a time to a given nucleus will eventually lead to a newly formed nucleus that immediately decays by emitting a proton (or neutron). Colloquially speaking, the nucleon has "leaked" or "dripped" out of the nucleus, hence giving rise to the term "drip line".

The experimentally added proton is bound, if it is in the established drip line for the nucleus species under study, and unbound if it is beyond , in the continuum.

Reading the article may help you in your question, and thank you for asking it , because I learned something new today.