  Alpha-alpha scattering is discussed in terms of a chiral two pion exchange
potential which turns out to be attractive and singular at the origin, hence
demanding renormalization. When 8Be is treated as a resonance state a model
independent correlation between the Q-factor and lifetime 1/Gamma for the decay
into two alpha particles arises. For a wide range of parameters compatible with
potential model analyses of low energy pi-alpha scattering it is found Gamma =
4.4(4)eV} in fairly good agreement with the experimental value Gamma = 5.57
(25) eV. The remaining discrepancy as well as the phase shift up to ELAB=15MeV
could be accommodated by the leading nuclear peripheral contributions due to
the 3H+p and 3He+n continuum.
