Effective field theory description of halo nuclei

Abstract

Abstract. Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4 He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.arXiv:1702.08605v2 [nucl-th] 5 Nov 2017 EFT for halo nuclei 2

D*D*D¯ and D*D*Valderrama1 2018Phys. Rev. D144110View full textAdd to dashboardCite

“…This spectrum, originally theorized by Efimov in the seventies [1], has been confirmed experimentally with cesium atoms a decade ago [2]. The relevance of the Efimov effect [3,4] is not limited to atomic physics, but extends to nuclear physics where it might play an important role in the binding of the triton [5][6][7], the three-alpha structure of Carbon-12 [8] or two-neutron halo nuclei [9,10]. The Efimov effect also extends to other three-body systems in the unitary limit: relevant to the present investigation is the case of two identical noninteracting boson of species A and a third particle of species B that interacts resonantly with the other two, i.e., the AB scattering length diverges.…”

Sensitivity of one-neutron knockout to the nuclear structure of halo nuclei

“…As explained in the Introduction, halo nuclei exhibit a clear separation of scales between the size of the core R core and the size of the halo R halo . The Halo-EFT approach [8,9] uses this separation of scale to expand the low-energy behaviour of the 10 Be-n system with R core /R halo ∼ 1/3 as expansion parameter. Following previous works [12,13], we use the Halo-EFT at next-to-leading order (NLO) to construct the c-n potential per partial-wave lJ.…”

Turning the nuclear energy density functional method into a proper effective field theory: reflections

“…Phenomenology Effective field theory (EFT) nucleons as confined quarks/gluons constituent quark model chiral quark model [6] inter-nucleon forces meson exchange models chiral EFT with nucleons, [∆s,] pions [7] universal large-scattering-length physics and halo nuclei effective range expansion and cluster models pionless EFT: nucleons only [7] or nucleons and clusters (halo) [8] saturation, pairing, shell structure energy density functionals What goes here??? low-lying excitations, superfluidity nuclei as Fermi liquids [9] EFT at the Fermi surface [10,11] collective rotational/vibrational motions of deformed nuclei collective models effective theory for deformed nuclei: systematic collective dofs [12] the pairing gap.…”

“…Engel and other authors have addressed this issue some time ago [110,111,112,113,114,115,116,26,117], with a consensus that HK existence proofs for DFT are still well founded, but for internal densities (e.g., meaning independent of the center-of-mass motion when considering broken translational symmetry). 8 Wave function methods have several related strategies for dealing with the "center of mass" (COM) problem:…”