Description
The electromagnetic (EM) moments and transitions in atomic nuclei provide fundamental insights into the nuclear structure and great progress has been achieved in past decades. However, the experimental deviation on EM moments and the 50-year-old quenching puzzle of beta decays indicate the impact of many-body contributions to the EM structure is non-negligible.
In recent years, the ab-initio calculations have explored the EM observables and weak transitions with contributions beyond the standard one-body operators. In Ref. [1], it is proposed that the missing nuclear correlations and the neglected contributions from meson-exchange currents are possible causes of the quenching phenomenon in beta decays.
More recently, Refs. [2, 3] focused on the magnetic moments from deuteron up to bismuth, including both manybody correlations and the leading EM two-body currents (2BC). On the other hand, the nuclear DFT can provide a global description of nuclear electric quadrupole and magnetic dipole moments, for example in one-particle and one-hole neighbors of doubly magic nuclei [4] or in open shell nuclei [5]. In our presentation, we introduce the first implementation of 2BC based on nuclear DFT in Jyväskylä-York collaboration to explore the contribution of higher-order current operators to magnetic dipole moments. The implementation is based on a use of auxiliary spherical harmonic oscillator basis, on which the two-body magnetic operator matrix elements are calculated. With use of unitary transformation, we can then compute the contribution of two-body currents on the magnetic moment for angular-momentum projected, deformed open shell nuclei. Further calculations are currently in progress.
[1] P. Gysbers et al., Nature Phys. 15, 428 (2019).
[2] R. Seutin et al., Phys. Rev. C 108, 054005 (2023).
[3] T. Miyagi et al., arXiv 2311, 14383 (2023).
[4] P. Sassarini et al., J. Phys. G Nucl. Part. Phys. 49, 11LT01 (2022).
[5] J. Bonnard et al., Phys. Lett. B 843, 138014 (2023)
