Polarization Dependence of the Specific Heat and the Origin of the Effective Mass in Liquid 3He

The enhanced effective mass of liquid 3 He has been alternatively ascribed to the large spin fluctuations in this system (nearly ferromagnetic model) or to local correlations effects (nearly localized model). We recently measured that polarizing liquid 3 He decreases its specific heat. We present our experiment, and discuss its implications in this theoretical context.