Anomalous viscous behavior of superfluidHe3at high magnetic field

We have measured the behavior of a vibrating-wire viscometer in superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ in the ${\mathrm{A}}_1$ and ${\mathrm{A}}_2$ phases in magnetic fields up to 9.2 T and at various pressures. In reduced units the viscosity in the ${\mathrm{A}}_1$ phase is, within our accuracy, independent of magnetic field and displays a minimum as a function of temperature for sufficiently high magnetic fields. Slightly below the ${\mathrm{A}}_2$ transition the viscosity shows an anomalous dip, which could indicate a new phase or a textural transformation. We offer a preliminary explanation for the observed anomalies.