Role of the angular-correlation analysis in α-clustering studies

The possibilities offered by the b-α angular-correlation analysis of X(a, b) Y(α)X processes as a ''diagnostic'' tool in order to investigate on the highly excited α-unbound states populated in α-transfer reactions are emphasized. Indeed these analyses, providing unambiguous spectroscopic information, besides spin-parity assignments, allow us a different and complementary investigation of the system (α+X)=Y, observed in the study of α-particle resonance scattering from the X-nucleus. Some applications and examples concerning highly excited α-unbound states in 20Ne are considered. Moreover, some ideas about what type of experiments might be performed and which nuclear-structure information is obtainable from such experiments are given