  We investigate charge fractionalizations in artificial Tomonaga-Luttinger
liquids (TLLs) composed of two capacitively coupled quantum Hall edge channels
(ECs) in graphene. The interaction strength of the artificial TLLs can be
controlled through distance W between the ECs. We show that the
fractionalization ratio r and the TLL mode velocity v vary with W. The
experimentally obtained relation between v and r follows a unique function
predicted by the TLL theory. We also show that charged wavepackets are
reflected back and forth multiple times at both ends of the TLL region.
