Nodal electronic scattering rates, T*, and the phase diagram in hole doped cuprate superconductors

Based upon detailed angle resolved photoemission spectroscopy measurements of a wide range of doping of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$, we present a unified phenomenology for the non-Fermi liquid normal-state interactions (scattering rates) in the nodal direction, which we show are dominated by a single parameter that smoothly varies with doping. When viewed over typical experimental temperature ranges this phenomenology has a curvature change that mimics the T* ``pseudogap'' temperature scale observed in transport experiments, including the possible quantum critical point.