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

TL;DR

This paper uses the complex scaled hyperspherical adiabatic expansion method to analyze the momentum and energy distributions of alpha particles from decaying low-lying $^{12}$C resonances, highlighting decay mechanisms and correlations.

Contribution

It provides detailed calculations of decay properties and momentum correlations for various $^{12}$C resonances, including natural and unnatural parity states, using an advanced theoretical approach.

Findings

Natural parity states decay mainly sequentially via $^{8}$Be ground state.

Unnatural parity states decay predominantly directly to the continuum.

Presented Dalitz plots and momentum correlation data.

Abstract

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.