  The Ultra High Energy Cosmic Ray UHECR, by UHE neutrino-relic neutrino Z
showering in Hot Dark Halos HDM, should exhibits an energy spectra and an
anisotropy reflecting (also) the relic neutrino masses and their hierarchical
HDM halo clustering. A twin light neutrino mass splitting may reflect to twin Z
resonance and into a complex UHECR spectra modulation, a twin bump, at the edge
at highest GZK energy cut-off. Each possible neutrino mass associates a
characteristic dark halo size (galactic, local, Super Cluster) and its local
anisotropy due to our peculiar position within that dark matter distribution. A
neutrino HDM halo around a Mpc will allow to the UHECR neutron secondary
component at E_n> 10^{20} eV (due to Z decay) to arise playing a role
comparable with the charged p- anti{p} ones. Their un-deflected n-anti{n} (or
decayed p-anti{p}) flight is shorter leading to a prompt and hard UHECR trace
pointing toward the original UHECR source direction. The direct p -anti{p}
pairs are split and spread by random magnetic fields into a more diluted and
smeared UHECR signal around the original source direction. TeVs signals by
synchrotron radiation must also mark the Z-WW Showering. The UHE Neutrino- Z
showering signatures may be already found in recent (and future) events in
AGASA (and Auger) data. The observed hard doublet and triplets spectra, their
time and space clustering already favour the rising key role of UHECR neutron
secondaries originated by Z tail shower.
