Quartets reexamined

Alpha spectroscopic factors for quartet wave functions are recalled for identical chains, which correspond to positive natural parity states. A generalization is presented for nonidentical chains which can give rise to negative natural parity states. Applications to the 0{ital f}-1{ital p} shell quartet structures observed in the ({sup 16}O,{sup 12}C) and ({sup 6}Li,{ital d}) reactions are given for the population of the first 2{sup +} excited state and for the population of low-lying 3{sup {minus}} excited states. {copyright} {ital 1996 The American Physical Society.}