Wikipedia:Articles for deletion/Planck particle
http://scholar.google.com/scholar?q=%22planck%20particle%22 Google Scholar 180 hits http://scirus.com/srsapp/search?q=%22planck+particle%22&t=all&sort=0&g=s Scirus 77 hits, among them articles in Foundations of Physics Letters, Chaos, Solitons & Fractals, Astronomy and Astrophysics, Progress in Physics (doesn't look terribly "mainstream", though) , Astroparticle  Physics, Physical Review D, Astrophysics and Space Science, Astrophysical Journal, MNRAS, European Journal of Physics. Passes  with flying colors, everything else is about content
— NONE, NONE
Stance: keep
Cited policy: WP:N (Wikipedia:Notability)