The 15N(d, n) 16O reaction and states in 16O

Abstract

Bombardment of a gaseous 15N target with deuterons has given absolute differential cross sections for the 15N(d, n) 16O reaction. Complete angular distributions, taken from 0° to 150° (lab) at 4.83 and 5.84 MeV bombarding energy were analyzed with a combination of DI and CN computer programs to derive l p values and spectroscopic factors. Yield curves taken at an angle of 10° with 0.5 MeV steps from 2.5 MeV to 6.0 MeV have also been analyzed with this combination of computer programs to give energy-averaged spectroscopic factors. The states observed and the l p values are generally in agreement with those from previous (τ, d) experiments. The present results disagree with them, however, on summed strengths. Whereas the (τ, d) strengths essentially fulfill the sum-rule expectations for both the T = 0 and T = 1 components of the 2 s 1 2 and 1 d 5 2 configurations in the observed states the (d, n) results do not, thereby implying greater spreading of the strength. We observe the following fractions of the sum rule values: (2 s 1 2 T = 0): 0.48; (2 s 1 2 , T = 1): 0.60; (1 d 5 2 , T = 0): 0.91; and (1 d 5 2 , T = 1): 0.61 . There is no T-dependence of the (d, n) and (τ, d) differences. These differences, as well as averages from all experiments are compared with shell-model calculations, and these results infer greater spreading of 2 s 1 2 strength than models show. To aid in discussing transition strengths we define and use a new “fractional transfer strength” which takes the value unity for any single-particle transfer.