Quasiparticle Thermal Hall Angle and Magnetoconductance inYBa2Cu3Ox

We present a way to extract the quasiparticle thermal conductivity ${\kappa }_e$ and mean free path in ${\mathrm{YBa}}_2{\mathrm{Cu}}_3{\mathrm{O}}_x$ using the thermal Hall effect and the field dependence of ${\kappa }_e$. The results compare well with heat capacity experiments. Moreover, we find a simple relation between the thermal Hall angle ${\theta }_Q$ and the $H$ dependence of ${\kappa }_e$, as well as numerical equality between ${\theta }_Q$ and the electrical Hall angle. The results also reveal an anomalously anisotropic scattering process in the normal state.