The 5$\alpha$ condensate state in $^{20}$Ne
Résumé
The formed $^{4}$He (α) clusters consisting of two neutrons and two protons can be a building block in light nuclear systems. Intriguingly, these alpha clusters could potentially form alpha condensate states within the nuclear system. The Hoyle state at 7.65 MeV in $^{12}$C, which plays an essential role in stellar nucleosynthesis, is now considered to be a phase transition, namely the 3α Bose-Einstein condensate. Confirming the existence of Hoyle-analog states in Nα nuclei (N > 3) remains a major challenge. Here we show microscopic five-body calculations for the $^{20}$Ne nucleus. We find that one excited 0$^{+}$ state has a distinct gas-like characteristic and represents the condensate state. Identifying the 5α condensate state is an important step in establishing the concept of α condensation in nuclear fermion systems.