  We present a systematic study of 400 combinations of the charged lepton and
neutrino mass matrices with six vanishing entries or texture zeros. Only 24 of
them, which can be classified into a few distinct categories, are found to be
compatible with current neutrino oscillation data at the $3\sigma$ level. A
peculiar feature of the lepton mass matrices in each category is that they have
the same phenomenological consequences. Taking account of a simple seesaw
scenario for six parallel patterns of the charged lepton and Dirac neutrino
mass matrices with six zeros, we show that it is possible to fit the
experimental data at or below the $2\sigma$ level. In particular, the maximal
atmospheric neutrino mixing can be reconciled with a strong neutrino mass
hierarchy in the seesaw case. Numerical predictions are also obtained for the
neutrino mass spectrum, flavor mixing angles, CP-violating phases and effective
masses of the tritium beta decay and the neutrinoless double beta decay.

High Energy Physics - Phenomenology