Scattering rate anisotropy in the pseudogap state of BSCCO

We study quasi-particle lifetime anisotropy in BSCCO as a function of tempe rature and doping by relaxational analysis of symmetrized Raman response fu nctions. For moderately underdoped BSCCO the pseudogap behavior manifests i tself in anisotropic suppression of the low-frequency scattering rates, sha rper in the vicinity of (pi, 0) and equivalent points of the Brillouin zone , or the hot spots, and milder in the vicinity of (pi/2, pi/2) points, or t he cold spots. With stronger underdoping the scattering rate suppression be comes more pronounced and isotropic.