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f i core by f$_{core}$ in eq. 2 changes the curve only slightly. Its form is dominated by the difference between < p$_{T}$ >$_{core}$ and < p$_{T}$ >$_{corona}$ . Tab.I summarizes the experimental < p i T >$_{corona}$ and < p i T >$_{core}$ which enter our calcula- tions and which are taken from pp and central heavy ion collisions. PHENIX has measured very peripheral heavy ion collisions. The < p$_{T}$ > value there coincide within the error bars with the STAR pp data. We note that < p i T >$_{corona}$ / < p i T >$_{core}$ varies from .81 for pions to .62 for protons. 

By construction the core - corona model correlates the < p i T > values of peripheral heavy ion reactions with those observed in pp. This correlation is shown in fig.4. It displays < p i T >$_{peri}$ / < p i T >$_{core}$ as a function of < p i T >$_{corona}$ / < p i T >$_{core}$ , using eq.2, for different hadron species. The experiential data show this correla- tion as well, it is even stronger there. Thus also in exper- iment the value of < p i T > in peripheral reactions is small as compared to that in central collisions for those hadrons for which < p i T > measured in pp is small as compared to < p i T > measured in central heavy ion collisions. This correlation is far from being trivial. If, as often assumed, the heavy ion collision can be described by hydrodynam- ical calculations we do not expect any correlation be- tween peripheral heavy ion data and pp data. Therefore the correlations observed in fig. 4 support the validity of the core - corona approach and questions whether hy- drodynamical calculations are the proper tool to describe non-central heavy ion reactions. 

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Corona particles do not form a thermal equilibrium with the core particles but decay like pp collisions and hence isotropically. Only the core particles feel the eccen- tricity of the overlap region. Because M charged particles core ≈ M charged particles corona , v$_{2}$/ϵ$_{part}$ is expected to be ∝ f$_{core}$ and therefore the expected centrality dependence of v$_{2}$/ϵ$_{part}$ is that of f$_{core}$ . This allows for some immediate pre- dictions. Because f$_{core}$ is similar in central CuCu and 

