Stable Spin Precession at one Half of Equilibrium Magnetization in Superfluid 3He-B

New modes of spin precession have been observed in superfluid {sup 3}He-{ital B} with a precessing magnetization M=pM{sub eq}, where p=1, (1)/(2), and {approx}0. These dynamic order parameter states are the first examples of stable precession with a magnetization different from the equilibrium value M{sub eq}. The p=(1)/(2) mode is the second example of a phase-coherent state of a spin superfluid. The new states can be excited close to T{sub c} in the range 1-T/T{sub c}{approx_lt}0.02 where dissipation is low and the energy barriers between the different local minima of the spin-orbit energy are small. {copyright} {ital 1996} {ital The American Physical Society}