The center of the particle is not a black hole because \(\psi=0\) at \(x=0\). Or is it?
How big SHOULD a particle be? The bound of the particle is where, from the surface of the particle, the total acceleration that a test particle experiences on moving inwards due to \(F_{\rho}\), brings it to light speed \(v_x=c\) along a radial direction. In this way, the particle is able to recycles itself.
\(\psi\) is on a Möbius strip, drawn at its belly towards the center, accelerating to light speed only to return to the same point with light speed, once again drawn at its belly further along the strip towards the center.
For energy density, \(\psi=0\) at \(x=0\) but kinetic energy of the test point, \(KE_{max}=\cfrac{1}{2}mc^2\) at \(x=0\).
Have a nice day.