Experimental Investigation of Highly Excited States of the [sup 5,6]He and [sup 5,6] Li Nuclei in the ([sup 6]Li, [sup 7]Be) and ([sup 6]Li, [sup 7]Li) One-Nucleon Pickup Reactions.

The ([sup 6]Li, [sup 7]Be) and ([sup 6]Li, [sup 7]Li) reactions on [sup 6]Li and [sup 7]Li nuclei were investigated in the angular interval 0°–20° in the laboratory system at a [sup 6]Li energy of 93 MeV. In addition to low-lying states of the [sup 5,6]He and [sup 5,6]Li nuclei, broad structures were observed near the t([sup 3]He) + d and t([sup 3]He) + t thresholds at the excitation energies of 16.75 (3/2[sup +]) and ∼20 MeV (for [sup 5]He), 16.66 (3/2[sup +]) and ∼20 MeV ([sup 5]Li), 14.0 and 25 MeV ([sup 6]He), and ∼20 MeV ([sup 6]Li). The angular distributions measured in the [sup 7]Li([sup 6]Li, [sup 7]Be)[sup 6]He reaction for transitions to the ground state (0[sup +]) and excited states at E[sub x] = 1.8 MeV (2[sup +]) and 14.0 MeV of the [sup 6]He nucleus were analyzed by the finite-range distorted-wave method assuming the 1p- and 1s-proton pickup mechanism. The ([sup 6]Li, [sup 7]Be) and ([sup 6]Li, [sup 7]Li) reactions were shown to proceed predominantly through the one-step pickup mechanism, and the broad structures observed at high excitation energies are considered as quasimolecular states of the t([sup 3]He) + d and t([sup 3]He) + t types.© 2002 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]