Figure 5. Γ-resonances at different modified cyclotron energies.

We measure for both isotopes various Γ-resonances at different modified cyclotron energies. Here we show the extracted mean values Γ_mean, normalized by the constant values: in a and in b in dependence of the modified cyclotron energy, which is proportional to the squared amplitude U_exc of the first excitation pulse. The slope is mainly given by the relativistic mass shift in the cyclotron frequency. The indicated error bars illustrate the statistical uncertainty of the weighted maximum-likelihood fit (see the dark-shaded area in Fig. 2c).