Pressure Dependence of the Specific-Heat Jump at the Superfluid Transition and the Effective Mass ofHe3

The specific heat of liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ has been measured from 1 to 10 mK between 0 and 32.5 bars. The values implied for the effective mass are considerably smaller than the currently accepted ones. Near zero pressure the specific-heat jump is close to the BCS value 1.43, and at 32.5 bars it has reached 1.90 in the $B$ phase and 2.04 in the $A$ phase. The temperature dependence of the specific heat in the $B$ phase agrees with a model of Serene and Rainer. The latent heat at the $A-B$ transition has been measured.