  The "metallic" regime of holes in GaAs/AlGaAs heterostructures corresponds to
densities where two splitted heavy hole bands exist at a zero magnetic field.
Using Landau fan diagrams and weak field magnetoresistance curves we extract
the carrier density in each band and the interband scattering rates. The
measured inelastic rates depend Arrheniusly on temperature with an activation
energy similar to that characterizing the longitudinal resistance. The
"metallic" characteristics, namely, the resistance increase with temperature,
is hence traced to the activation of inelastic interband scattering. The data
are used to extract the bands dispersion relations as well as the two
particle-hole excitation continua. It is then argued that acoustic plasmon
mediated Coulomb scattering might be responsible for the Arrhenius dependence
on temperature. The absence of standard Coulomb scattering characterized by a
power law dependence upon temperature is pointed out.
