Energy Dependence and Spectroscopy of theO16(p, d)O

Abstract

A systematic study of t the extraction of spectroscopic factors for the (p, d) reaction on light nuclei and the difficulties encountered in obtaining reasonable distorted-wave Born approximation (DWBA) fits to the shapes of the angular distributions has been made. Deuteron spectra and angular distributions were measured for the 1G 0(p, d) 15 0 reaction for 21. 27-, 25.52-, 31.82-, 38.63-, and 45.34-MeV incident protons. The elastic scattering of protons from 16 0 was measured over the same energy range and used to obtain proton opticalmodel parameters. Present results indicate that consistent spectroscopic information can be obtained from DWBA calculations when the deuterons in the exit channel have an energy greater than 20 MeV. Approximately 30% of the 1^3/2 strength appears to be missing from the 6.18-MeV, f~ level of 15 0, and a large fraction of that strength appears in the 9.60-and 10.46-MeV levels. Small 2s-ld admixtures were observed in the ground state of 16 0, and excitation of a J + level is observed. This excitation is a possible candidate for a two-step excitation process.

On mirror states of negative parity in mass 15 nuclei

“…The centroids of the triton groups corresponding to an excitation energy of 9.61 and 10.46 MeV in ~so agree with the positions of known [4] negative parity levels which have also been selectively excited in a previous 160(p, d)lSO experiment [6]. The energy calibration of the analog z groups yielded a less evident result.…”

“…The I,= 1 transfer observed in the 160(p, d)150 (10.46 MeV) reaction [6] implies J~= 1/2-or 3/2-for this level. A unique spin assignment cannot be made at the moment.…”

“…Since the l= 1 nature of the angular distributions has been established both in 160(p, d)150 (Ref. [6]) and 160(d,z)lSN (Ref. [5]) the previous positive parity assignment for the 9.93 and 10.70 MeV levels in 15N must be abandoned, unless the excitation of previously unreported levels is assumed.…”

Effect of Tensor Interactions in16O Studied via (p,d) Reaction

“…1(b) were estimated and subtracted. Other data were taken from the previous measurements with proton energies between 45 and 800 MeV [11,12]. Notice that the ratios for the positive-parity states increase drastically by a factor of over 30 from q transfer 0.3 fm −1 to 3.0 fm −1 , whereas the ones for the negative-parity states only triple.…”

The calculation of logft values and spectroscopic factors for nuclei in the mass range 10?15

“…Judging by the example of the ground state, however, more data would appear to be necessary before definite conclusions may be made about this case. According to Snelgrove and Kashy [60], the inclusion of (s, d) 2 components results in a splitting of the single theoretical level into two levels (experimentally at 9.17 and 10.43 MeV)which share the total l p strength (see also [59]). …”