27Al(d,3He)26Mg reaction at 29 MeV.

Abstract

The $^{27}\mathrm{Al}$(d${,}^{3}$He${)}^{26}$Mg reaction has been investigated at 29 MeV incident energy. Observations using a split-pole magnetic spectrograph have been made of 65 levels of $^{26}\mathrm{Mg}$ in the range of excitation energy between 0 and 9.7 MeV. These levels can be identified with the known states of $^{26}\mathrm{Mg}$, which by other techniques have been assigned excitation energies with precisions of 3 keV or better. Information about the orbital angular momentum (with associated conclusions about J and \ensuremath{\pi}) and the single-nucleon spectroscopic factors of about 40 of these $^{26}\mathrm{Mg}$ levels have been obtained through distorted-wave Born approximation (DWBA) analyses of measured angular distributions. Eight levels which are populated through the pickup of a ${\mathit{l}}_{\mathit{p}}$=1 proton have been observed at ${\mathit{E}}_{\mathit{x}}$=6.878, 7.694, 7.824, 8.050, 8.902, 9.042, 9.239, and 9.618 MeV. The two most strongly excited of these levels (${\mathit{E}}_{\mathit{x}}$=7.824 and 9.042 MeV) were attributed in a previous study of the same reaction to the population of 1p hole states. The observed angular distributions of two ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=${6}^{+}$ levels are reproduced with ${\mathit{l}}_{\mathit{p}}$=4 DWBA calculations which assume g components in the ground state of $^{27}\mathrm{Al}$. The excitation energies and spectroscopic factors for positive parity states are compared with the results of a recent, complete sd-shell space, shell-model calculation. New spectroscopic information is extracted from this comparison and from the comparison of the present results with previous knowledge.