Eur. Phys. J. A (2017) 53: 204
https://doi.org/10.1140/epja/i2017-12404-5

Regular Article - Theoretical Physics

Effective field theory for triaxially deformed nuclei

¹ Physik-Department, Technische Universität Müchen, D-85747, Garching, Germany
² State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, 100871, Beijing, China
³ Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115, Bonn, Germany
⁴ Institute for Advanced Simulation, Institut für Kernphysik, Jülich Center for Hadron Physics and JARA-HPC, Forschungszentrum Jülich, D-52425, Jülich, Germany
⁵ School of Physics and Nuclear Energy Engineering, Beihang University, 100191, Beijing, China
⁶ Department of Physics, University of Stellenbosch, Stellenbosch, South Africa

^* e-mail: qbchen@pku.edu.cn

Received: 13 July 2017
Accepted: 5 October 2017
Published online: 24 October 2017

Abstract

Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the band in the low spin region are well described. The deviations for high-spin states in the bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation.