Momentum distributions of $α$-particles from decaying low-lying $^{12}$C-resonances

R. Alvarez-Rodriguez, A. S. Jensen, E. Garrido, D. V. Fedorov, H. O. U. Fynbo

Published 2008-05-09Version 1

The complex scaled hyperspherical adiabatic expansion method is used to compute momentum and energy distributions of the three $\alpha$-particles emerging from the decay of low-lying $^{12}$C-resonances. The large distance continuum properties of the wave functions are crucial and must be accurately calculated. We discuss separately decays of natural parity states: two $0^+$, one $1^{-}$, three $2^+$, one $3^-$, two $4^+$, one $6^+$, and one of each of unnatural parity, $1^{+}$, $2^-$, $3^+$, $4^-$. The lowest natural parity state of each $J^{\pi}$ decays predominantly sequentially via the $^{8}$Be ground state whereas other states including unnatural parity states predominantly decay directly to the continuum. We present Dalitz plots and systematic detailed momentum correlations of the emerging $\alpha$-particles.