Ab Initio MCSM Calculation for Reduced Matrix Elements of E2 Operator for A=10 Nuclei

The reduced matrix elements of ê2 operator for ¹⁰Be low-lying states are evaluated with the no-core Monte Carlo shell model, which has been used to investigate the structure of light nuclei in an ab initio sense recently. The MCSM calculation converges within 20 MCSM dimensions. These MCSM results show good agreement with new experimental data and other ab initio calculations. The reduced matrix elements are investigated in terms of single-particle orbits contribution. It is found that the transition among p-shell orbits is dominant. The triaxial deformation of ¹⁰Be, as well as its mirror nucleus ¹⁰C, is also discussed. Meanwhile, the importance of p-shell orbits to the triaxiality is addressed.