SPECTROSCOPIC FACTORS FROM ANALOGUE RESONANCES

Three methods for the determination of spectroscopic factors from data on isobaric analogue resonances (IAR) are compared It is shown numerically that, in general, all three lead to different values of the spectroscopic factor. The differences amount to as much as 50% if the same potentials are used The reasons for these differences are exhibited, and their physical origin is discussed It turns out that the discrepancies arise from (1) the treatment of internal mixing, (11) the statistical assumptions which are introduced in order to perform the averaging over the fine structure of the IAR, (111) the treatment of a single-particle resonance which often occurs in the proton channel some MeV below the IAR. The differences could partly be resolved if the resonance mixing phase could be determined experimentally. © 1969.