A. Parikh, K. Wimmer, T. Faestermann, R. Hertenberger, H. -F. Wirth, A. A. Chen, J. A. Clark, C. M. Deibel, C. Herlitzius, R. Krucken, D. Seiler, K. Setoodehnia, K. Straub, C. Wrede
Model predictions of the amount of the radioisotope 26Al produced in
hydrogen-burning environments require reliable estimates of the thermonuclear
rates for the 26gAl(p,{\gamma})27Si and 26mAl(p,{\gamma})27Si reactions. These
rates depend upon the spectroscopic properties of states in 27Si within about 1
MeV of the 26gAl+p threshold (Sp = 7463 keV). We have studied the
28Si(3He,{\alpha})27Si reaction at 25 MeV using a high-resolution
quadrupole-dipole-dipole-dipole magnetic spectrograph. For the first time with
a transfer reaction, we have constrained J{\pi} values for states in 27Si over
Ex = 7.0 - 8.1 MeV through angular distribution measurements. Aside from a few
important cases, we generally confirm the energies and spin-parity assignments
reported in a recent {\gamma}-ray spectroscopy study. The magnitudes of neutron
spectroscopic factors determined from shell-model calculations are in
reasonable agreement with our experimental values extracted using this
reaction.
View original:
http://arxiv.org/abs/1112.3181
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