arXiv:2508.15226v1 Announce Type: new
Abstract: There have been several reported values for the nuclear quadrupole moment of $^{43}$Ca, but significant discrepancies exist among these reported values, ranging from (-0.0408(8))~b to (-0.065(20))~b. In this work, we performed an accurate calculation of the electric field gradients of the (4s4p~^3!P_{1}), (4s4p~^3!P_{2}) and (4s3d~^1!D_2) states in the $^{43}$Ca atom using a hybrid method. This hybrid method integrates the advantages of the configuration interaction method and the coupled-cluster method, and can simultaneously account for core-core, core-valence, and valence-valence correlations. By combining our calculated results with the experimental values of the electric quadrupole hyperfine-structure constants of these three states, an accurate and reliable nuclear quadrupole moment of $^{43}$Ca was determined to be (-0.0479(6))~b, which could be recommended as a reference for (^{43}text{Ca}).