Effective field theory for triaxially deformed nuclei

TL;DR

This paper extends effective field theory to model the rotational behavior of triaxially deformed nuclei, deriving a Hamiltonian that accurately describes energy spectra and can be generalized further.

Contribution

It introduces a next-to-leading order Hamiltonian within EFT for triaxial nuclei and demonstrates its effectiveness compared to existing models.

Findings

NLO corrections improve spectral descriptions

Ground state and gamma bands are well modeled

Potential for extending EFT to odd-mass nuclei

Abstract

Effective field theory (EFT) is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. A Hamiltonian, called the triaxial rotor model (TRM), is obtained up to next-to-leading order (NLO) within the EFT formalism. Its applicability is examined by comparing with a five-dimensional collective Hamiltonian (5DCH) for the description of the energy spectra of the ground state and $\gamma$ band in Ru isotopes. It is found that by taking into account the NLO corrections, the ground state band in the whole spin region and the $\gamma$ band in the low spin region are well described. The results presented here indicate that it should be possible to further generalize the EFT to triaxial nuclei with odd mass number.