Effective theory for deformed nuclei

Abstract

Techniques from effective field theory are applied to nuclear rotation. This approach exploits the spontaneous breaking of rotational symmetry and the separation of scale between low-energy Nambu-Goldstone rotational modes and high-energy vibrational and nucleonic degrees of freedom. A power counting is established and the Hamiltonian is constructed at next-to-leading order.

Effective field theory for finite systems with spontaneously broken symmetry

“…[13,30,31]. For deformed nuclei, the presented EFT generalizes the simpler construction of an effective theory proposed recently [32]. Based on symmetry principles alone, our model-independent approach re-derives some of the well-known results for collective nuclear models.…”

“…They describe global rotations of the finite system and are factored out [18]. They are not Nambu-Goldstone modes but upon quantization generate rotational bands [32,42]. The fields x(θ, φ, t) and y(θ, φ, t) with |x|, |y| ≪ 1 generate small-amplitude vibrations of the constituents.…”

“…(18) has the form of a general rotation with Euler angles (α ′ , β ′ , γ ′ ), with explicit expressions given in Ref. [32]. Thus,…”

Effective field theory for triaxially deformed nuclei

“…In the previous version of the EFT for nuclear rotation [3], the authors focussed on deformed nuclei with axial symmetry. In that case the nuclear ground state is invariant under SO(2) rotations about the body-fixed symmetry axis, while SO(3) symmetry is broken by the deformation.…”

“…Since the initial paper in 2011 [3] they have completed a series of further works in Refs. [4][5][6][7][8][9][10].…”