We discuss possible parallel textures of the Yukawa coupling matrices in the
generaltwo-Higgs-doublet model (2HDM). In those textures the flavor changing
neutral currentsare naturally suppressed. Motivated by a phenomenologically
successful texturewith four texture zeros in the standard model, we propose a
predictive ansatz for the Yukawa coupling matrices with the same texture in the
general 2HDM. Compared with the six texture-zero based ansatz proposed by Cheng
and Sher, it is in a better agreement with the data of quark mixings and CP
violation. The four texture-zero based ansatz predicts a different hierarchy in
the Yukawa coupling matrix elements. As a consequence, in the lepton sector,
the related Yukawa couplings are less constrained by the experimental upper
bound of ΞΌβeΞ³, which allows significantly larger predictions for
other processes. The contributions from neutral scalar interactions to the
lepton number violation decay modes βββ1ββ2ββ3β are
calculated in both ansatz. It is shown that the predictions from the four
texture-zero based ansatz could be two order of magnitude greater than that
from the six texture-zero based one. The branching ratio of ΞΌβ3e and
Οβ3ΞΌ can reach 7.5Γ10β17 and 1.3\tiems 10^{-10}
respectively. The predicted ratio of Br(ΞΌβ3e)/Br(Οβ3e) is also
larger and almost parameter independent. Those differences make the two ansatz
to be easily distinguished by the future experiments.Comment: 12 pages, 2 figure