No-Core MCSM calculation for ¹⁰Be and ¹²Be low-lying spectra

The low-lying excited states of ¹⁰Be and ¹²Be are investigated within a no-core Monte Carlo Shell Model (MCSM) framework employing a realistic potential obtained via the Unitary Correlation Operator Method. The excitation energies of the 2⁺₁ and 2⁺₂ states and the B(E2; 2⁺₁,₂ → 0⁺g.s.) for ¹⁰Be in the MCSM with a standard treatment of spurious center-of-mass motion show good agreement with experimental data. Some properties of low-lying states of ¹⁰Be are studied in terms of quadrupole moments and E2 transitions. The E2 transition probability of ¹⁰C, the mirror nucleus of ¹⁰Be, is also presented with a good agreement to experiment. The triaxial deformation of ¹⁰Be and ¹⁰C is discussed in terms of the B(E2) values.