On closer inspection,
only solutions with v2=0 at x=xz are admissible in the post "Twirl Plus SHM, Spinning Coin" date 17 Jul 2015.
θ could be polarization measured from the vertical. Photons emission/absorption occurs at x=xz, at the center of the ψ cloud.
What if θ can be tuned, at 45o, the factor,
1−√sin(θ)cos(θ)=0 and
Ep=0
when θ=45o,
does the particle also vanishes? It is no longer emitting nor absorbing photons.