Low temperature specific heat of CeCu2Si2 under high pressure

Results of specific-heat-measurements on polycristalline CeCu2Si2 in the temperature range between. 3K and 2K under pressure up to 9.3 kbar are presented. The coefficient gamma(Tc) = c(Tc)/Tc of the electronic specific heat decreases monotonously by 42%. This behavior is supposed to be a consequence of a broadening with pressure of the Kondo resonance in the density of states. In distinct contrast to the superconducting transition temperature Tc, which increases only slightly with pressure, the specific heat discontinuity delta c (Tc) varies in a strong monotonous way. Two alternative explanations are suggested: high pressure may either change the anisotropy of the superconducting energy gap or the energy dependence of the Kondo-lattice quasiparticle density-of-states.