Could we keep it perpetually in an excited state that has no amplitude at the centre?
Re:Antiproton Orbiting Helium Ion
by marcosdumay on Wednesday March 16, 2022 @02:36PM
(#30702368)
It reaches the nucleus by a process of tunneling. You can never completely stop it, but it reacts exponentially to you increasing a barrier.
An excited state isn't a barrier, it's a state with a higher energy than ground state. Several non-ground-state orbitals have a wavefunction whose amplitude drops to zero toward the centre.
An electron won't tunnel to a location where its wavefunction amplitude is zero.
In other words, it is not so much the antiproton falling to the nuclear surface as much as the antiproton finding itself at the nuclear surface.
EDIT: The context is that the antiproton was in an orbital with large principal and azimuthal quantum numbers. Still, there would be some non-zero probability of the antiproton finding itself close to the nucleus, no?