New Arguments Concerning the EffectiveHe3Quasiparticle Interaction in SuperfluidHe4

By using the Woo—Tan—Massey theory of ${\mathrm{He}}^3$-${\mathrm{He}}^4$ solutions, an expression is derived for $V_0$, the long-wavelength limit of the effective ${\mathrm{He}}^3$ quasiparticle interaction in dilute ${\mathrm{He}}^3$-${\mathrm{He}}^4$ solutions. The expression supports the calculation of Eckstein, Eckstein, Kuper, and Ron, and indicates that the Baym, Bardeen, Pines result for $V_0$ is incorrect. Arguments are also given to suggest that $V_0$ may be positive definite at all pressures.