Rare $E 2$ Transition in $C^{13}$

By means of a coincidence method it is shown that the

\frac{5}{2} +

state of

C^{13}

at 3.86 Mev has an

E 2

branch of relative strength (9.3±2.0)×

10^{- 3}

to the ½+ state at 3.09 Mev. From consideration of the likely strengths of the competing

E 1

transition to the

\frac{3}{2} -

state at 3.68 Mev and the

M 2

transition to the ground state it is deduced that this branching ratio implies an

E 2

transition speed of the order of a single-particle (proton) unit. This in turn demands the substantial participation of at least one excited state of

C^{12}

in the parentage of at least one of the

C^{13}

states with respect to the

1 d

2 s

neutron. This eliminates in particular a

jj

-coupling description of

C^{13}

in which the two states in question are

1 d_{\frac{5}{2}}

and

2 s_{\frac{1}{2}}

neutron states and more generally a weak-coupling model in which the ground state of

C^{12}

is the unique parent for the

C^{13}

states (with respect to

1 d

and

2 s

neutrons).

This publication has 12 references indexed in Scilit:

RareE2Transition inC13