On Leggett's inequality for Balian-Werthamer liquids

It is shown that there exist such values of exchange Landau parameters for l = 1 and 3 and such spin-direct Landau parameter for l = 1, fulfilling Pomeranchuk stability conditions, that the normal system is stable whereas the Balian-Werthamer (BW) system is unstable. Our result makes inconsistent a rather widespread belief that the normal system, stable from the point of view of Pomeranchuk inequalities, can always pass to stable superfluid state. Above values of these parameters are far from their experimental data for liquid 3He. (orig.)