Investigation of deformation parameter β2 from reduced transition probabilities B (E2) at even-even 22−32Mg isotopes using different interactions

Edward Ameh Odumeke; Ahmed Hussein Ali; Johnson Akinade Bamikole; Joseph Omojola

doi:10.5455/EJSRR.20250416100426

Abstract
Aim: This work investigated the deformation parameter β2 from the reduced transition probabilities B (E2) for even-even 22−32Mg isotopes using different effective charges and interactions.
Methods: One-body transition matrix elements were calculated for each selected magnesium isotope using the NuShellX@MSU code within the sd-model space. Two interactions were used, SDBA and BKUOSD. Reduced transition probabilities B (E2) were calculated using various effective charges; NuShellX default effective charges (Nus), conventional effective charges (CON), standard effective charges, and Bohr–Mottelson effective charges (B-M). The size xparameter, b, was also determined for each isotope. Deformation parameters β2 were then calculated from the B (E2) values using the CON with both SDBA and BKUOSD interactions.
Results: B (E2) values calculated using the BKUOSD interaction were more accurate than those from the SDBA interaction. The deformation parameters β2 calculated using BKUOSD and SDBA interactions showed good agreement with experimental data.
Conclusion: Theoretical results using the BKUOSD interaction provide the best match to experimental data for B(E2) and β2, indicating its suitability for describing the structure of even-even magnesium isotopes in the sd-shell.

Key words: Transition rate; model space; deformation parameter; core polarization; effective charge; shell mode