  We evaluate the achievable maximum energy of nuclei diffusively accelerated
by shock wave in the jet of Cen A, based on an updated model involving the
stochastic magnetic fields that are responsible for recent synchrotron X-ray
measurements. For the maximum energy analysis, conceivable energy constraints
from spatiotemporal scales are systematically considered for the jet-wide
including discrete X-ray knots. We find that in the inner region within ~1
arcmin from galactic core, which includes knots AX and BX, proton and iron
nucleus can be accelerated to 10^{19}-10^{20} and 10^{21} eV (10-100 EeV and
ZeV) ranges, respectively. The upper cutoff energy of the very energetic
neutrinos produced via photopion interaction is also provided. These are
essential for identifying the acceleration site of the ultra-high energy cosmic
ray detected in the Pierre Auger Observatory, which signifies the arrival from
nearby galaxies including Cen A.
