S-MATRIX DESCRIPTION OF REFRACTIVE EFFECTS IN ONE-NUCLEON STRIPPING REACTIONS INDUCED BY α-PARTICLES ON 28Si

We analyze the angular distributions for the (alpha, 3He) and (alpha, t) re-actions on 28Si for projectile energies ranging from 50 to 120 MeV based on the partial-wave representation of the transfer amplitude expressed in terms of the S-matrices for the entrance and exit channels, with an emphasis on identifying Airy minima of various orders. The calculations have been performed using a six-parameter S-matrix model and S-matrix parameters obtained from the analysis of elastic scattering data. The first-and (or) second-order Airy minima are clearly identified in the analyzed transfer reaction angular distributions at intermediate angles. The detected Airy minima are found to be due to the interference between several inner and surface partial waves. The impact parameters of these waves are in the range of 1-6 fm, the upper boundary of which is less than the strong ab-sorption radius.

Automated summary

We analyzed the angular distributions of the (alpha, 3He) and (alpha, t) reactions on 28Si for projectile energies ranging from 50 to 120 MeV, using a partial-wave representation of the transfer amplitude expressed in terms of S-matrices for the entrance and exit channels. We focused on identifying Airy minima of different orders. The calculations were based on a six-parameter S-matrix model and S-matrix parameters obtained from the analysis of elastic scattering data. The results showed clear identification of first and (or) second-order Airy minima in the analyzed transfer reaction angular distributions at intermediate angles, which were attributed to interference between several inner and surface partial waves. The impact parameters of these waves ranged from 1-6 fm, with an upper boundary smaller than the strong absorption radius.