The spectroscopic quadrupole moment of the 21+ state of 12C: A benchmark of theoretical models

Electromagnetic properties of nuclei from first principles: a case for synergies between experiment and theory

“…Figure 6 a summarizes the experimental results to date of the spectroscopic quadrupole moment of the true0 2 + state of 12 C and how they compare with theory. The high energy of the true0 true0 2 + → 0 + γ-ray transition (4.44 MeV) and the low Coulomb-excitation cross-section make this a very challenging measurement, reflected in the limited number of experiments that have attempted this measurement [83–85]. It is interesting that the ab initio calculations [65,77–79] firmly predict true0 Q s ( 2 + ) ≈ +6 efm 2 .…”

“…Theoretical (blue-filled squares) and experimental values (black-filled triangles) for the ( a ) true0 Q s ( 2 1 + ) and ( b ) dimensionless ratio true0 B ( E 2 ; 0 1 + → 2 1 + ) / Q s 2 ( 2 1 + ) of 12 C. From the left to the right: in-medium no-core shell model (IM-NCSM) and importance truncated no-core shell model (IT-NCSM) using NN + 3N chiral EFT interactions [65,77], lattice EFT at LO [78], no-core ab initio Monte Carlo shell model using the Daejeon16 interaction [79], algebraic cluster model [80], global energy density functionals [81], shell-model calculations using variable and fixed effective charges ( true0 e e f f ) [82], experimental values measured by Vermeer et al . [83], Raju et al [84] and Saiz Lomas et al [85]. The shaded area follows the experimental values from the most recent experiment which delivered the most precise value to date for the true0 Q s ( 2 1 + ) [85].…”

“…[83], Raju et al [84] and Saiz Lomas et al [85]. The shaded area follows the experimental values from the most recent experiment which delivered the most precise value to date for the true0 Q s ( 2 1 + ) [85]. The figure is modified from [85] (Online version in colour.…”