  A recent polarized x-ray absorption experiment on the high temperature
cuprate superconductor Bi2Sr2CaCu2O8 indicates the presence of broken parity
symmetry below the temperature, T*, where a pseudogap appears in photoemission.
We critically analyze the x-ray data, and conclude that a parity-breaking
signal of the kind suggested is unlikely based on the crystal structures
reported in the literature. Possible other origins of the observed dichroism
signal are discussed. We propose x-ray scattering experiments that can be done
in order to determine whether such alternative interpretations are valid or
not.
