Structure of the doubly magic nuclei $^{208}$Pb and $^{266}$Pb from ab initio computations

Abstract: Theoretical studies indicate that the superheavy neutron-rich nucleus $^{266}_{\ 82}$Pb$_{184}$ is doubly magic and at the neutron drip line. While its density distributions and single-particle energies have been computed, the structure of this nucleus is yet unknown. We perform ab initio computations of $^{266}$Pb using an interaction from an effective field theory of quantum chromodynamics tuned only on properties of nuclei with $A \leq 4$. We validate our theoretical framework by computing the first $2^+$ and $3^-$ excited states of $^{208}$Pb, finding agreement with experimental data. We confirm that $^{266}$Pb is doubly magic and show that its $3^-$ state, located below the $2^+$ state, exhibits an excitation gap of 2.6 MeV with respect to the ground state. Our calculations also suggest that this nucleus is at the neutron drip line.