Cluster structure of 8p-4h states in ${}^{20}{Ne}$

The structure of high-lying states in

{}^{20}{Ne}

has been studied using the

{}^{12}C ({}^{12}C, α) {}^{20}{Ne}

reaction at

E ({}^{12}C) = 64 and 80

MeV. The spins and branching ratios to the

α

{}^{16}O

channel were determined by measuring double (

α - α

) and triple (

α - α - γ

) angular correlations. The branching ratios for decay to the

{}^{12}C

{}^{8}{Be}

channel were obtained from an

α

{}^{12}C

coincidence experiment. In addition to confirming the spins of several lower-lying states, we have made a spin assignment of

8^{+}

for the state at 18.538 MeV and also suggest assignments to states at 17.259 MeV (

7^{-}

), 20.478 MeV (

8^{+}

), and 24.378 MeV (

7^{-}

). The 13.927-MeV (

6^{+}

) state is assigned to the

K^{π} = 0_{2}^{+}

band, and it is suggested that this band also includes the

8^{+}

state at 20.478 MeV. The 18.538-MeV (

8^{+}

) state was found to have a large reduced width for decay into

{}^{12}C

{}^{8}{Be}

which, together with its small reduced width for decay to

α

{}^{16}O_{g . s .}

,suggests that it has a large

{}^{12}C

{}^{8}{Be}

cluster parentage. This state appears to be the

8^{+}

member of a new 8p-4h band which has the 12.436-MeV (

0_{6}^{+}

) state as its band head and the state at 15.159 MeV as its

6^{+}

member. The discovery of such a rotational band in

{}^{20}{Ne}

with a large

{}^{12}C

{}^{8}{Be}

cluster parentage and a large moment of inertia provides the first direct indication of correlations between the α clusters in 8p-4h states.

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Cluster structure of 8p-4h states inNe20