In order to describe the slow response of a glass former we discuss somedistribution of correlation times, e.g., the generalized gamma distribution(GG) and an extension thereof (GGE), the latter allowing to reproduce a simplepeak susceptibility such as of Cole-Davidson type as well as a susceptibilityexhibiting an additional high frequency power law contribution (excess wing).Applying the GGE distribution to the dielectric spectra of glass formersexhibiting no beta-process peak (glycerol, propylene carbonate and picoline) weare able to reproduce the salient features of the slow response (1e-6 Hz - 1e9Hz). A line shape analysis is carried out either in the time or frequencydomain and in both cases an excess wing can be identified. The latter evolvesin a universal way while cooling and shows up for correlation times tau_alpha >1e-8 s. It appears that its first emergence marks the break down of the hightemperature scenario of mode coupling theory. - In order to describe a glassformer exhibiting a beta-process peak we have introduced a distributionfunction which is compatible with assuming a thermally activated process incontrast to some commonly used fit functions. Together with the GGEdistribution this function allows in the frame of the Williams-Watts approachto completely interpolate the spectra, e.g. of fluoro aniline (1e-6 Hz - 1e9Hz). The parameters obtained indicate an emergence of both the excess wing andthe beta-process again at tau_alpha > 1e-8s.
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