Candidates for the 5$\alpha$ condensed state in ${}^{20}$Ne

TL;DR

This study provides the first strong evidence for candidate 5α condensed states in ${}^{20}$Ne, identified through inelastic scattering and decay measurements, supporting the existence of alpha-cluster condensed states in nuclei.

Contribution

The paper reports the experimental identification of new states in ${}^{20}$Ne that are strongly coupled to a candidate 4α condensed state in ${}^{16}$O, suggesting these are candidates for 5α condensed states.

Findings

Observed states at 23.6, 21.8, and 21.2 MeV in ${}^{20}$Ne.

Measured decay branching ratios consistent with alpha-cluster models.

Provided the first strong experimental evidence for 5α condensed states.

Abstract

We conducted the coincidence measurement of $\alpha$ particles inelastically scattered from ${}^{20}$Ne at $0^{\circ}$ and decay charged particles in order to search for the alpha-particle condensed state. We compared the measured excitation-energy spectrum and decay branching ratio with the statistical-decay-model calculations, and found that the newly observed states at $E_x$ = 23.6, 21.8, and 21.2 MeV in ${}^{20}$Ne are strongly coupled to a candidate for the 4$\alpha$ condensed state in ${}^{16}$O. This result presents the first strong evidence that these states are the candidates for the 5$\alpha$ condensed state.