“…Moreover, the Taub-NUT geometry possesses four Killing-Yano tensors, f (i) (iϭ1,2,3) and f Y , of valence 2, related to the hidden symmetries of the Taub-NUT geometry reflected by the existence of the nontrivial Stäckel-Killing tensors k (i) . 2,4,7,14 In this Kaluza-Klein geometry there is a pentad gauge fixing 15 where the massless Dirac field, , satisfies a simple gauge-covariant Dirac equation, D " ϭ0, where D " ϭi␥ 0 ץ t ϪD " s . 16,5,7,9 In the standard representation of the Dirac matrices ͓with diagonal ␥ 0 ͑Ref.…”