Range corrections for two-neutron halo nuclei in effective theory

Canham, David L.; Hammer, H.-W.

doi:10.1016/j.nuclphysa.2010.02.014

Cited by 46 publications

(44 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[39][40][41][42][43], with that theory extended to P -wave interactions in Refs. [44,45] and the results applied to various halo systems including [49], as well as to α-α interactions [50] and a number of two-neutron halos [51][52][53][54][55][56].…”

Section: B Why Effective Field Theory?mentioning

confidence: 99%

Combiningab initiocalculations and low-energy effective field theory for halo nuclear systems: The case of7Li+n→8Li+γ

2014

View full text Add to dashboard Cite

We report a leading-order calculation of radiative 7 Li neutron captures to both the ground and first excited state of 8 Li in the framework of a low-energy effective field theory (Halo-EFT). Each of the possible final states is treated as a shallow bound state composed of both n + 7 Li and n + 7 Li * (core excitation) configurations. The ab initio variational Monte Carlo method is used to compute the asymptotic normalization coefficients of these bound states, which are then used to fix couplings in our EFT. We calculate the total and partial cross sections in the radiative capture process using this calibrated EFT. Fair agreement with measured total cross sections is achieved and excellent agreement with the measured branching ratio between the two final states is found. In contrast,a previous Halo-EFT calculation [G. Rupak and R. Higa, Phys. Rev. Lett 106, 222501 (2011)] assumes that the n-7 Li couplings in different spin channels are equal, fits the P -wave "effectiverange" parameter to the threshold cross section for 7 Li + n → 8 Li + γ, and assumes the core excitation is at high enough energy scale that it can be integrated out.

show abstract

Section: B Why Effective Field Theory?mentioning

confidence: 99%

Combiningab initiocalculations and low-energy effective field theory for halo nuclear systems: The case of7Li+n→8Li+γ

2014

View full text Add to dashboard Cite

show abstract

“…Particularly exciting is the possibility that the Efimov physics [21], having been seen experimentally in recombination rates in cold atomic gases [22][23][24][25], could also exhibit its existence in halo nuclei [26]. A variety of s-wave 2n halos (e.g., 12 Be and 20 C) were investigated at leading [27] and next-to-leading [28] order in the M lo /M hi expansion by Canham and Hammer. Recently, Hagen et al proposed that 62 Ca could also be an s-wave halo that displayed Efimovian features [5]. The existence and universal features of s-wave 2n halos have also been studied by Yamashita et al in a renormalized zero-range model [29,30].…”

Section: Introductionmentioning

confidence: 99%

He6nucleus in halo effective field theory

2014

View full text Add to dashboard Cite

Background:In recent years properties of light rare isotopes have been measured with high accuracy. At the same time, the theoretical description of light nuclei has made enormous progress, and properties of, e.g., the helium isotopes can now be calculated ab initio. These advances make those rare isotopes an ideal testing ground for effective field theories (EFTs) built on cluster degrees of freedom. Purpose: Systems with widely separated intrinsic scales are well suited to an EFT treatment. The Borromean halo nucleus 6 He exhibits such a separation of scales. In this work an EFT in which the degrees of freedom are the valence neutrons (n) and an inert 4 He-core (α) is employed. The properties of 6 He can then be calculated using the momentum-space Faddeev equations for the αnn bound state to obtain information on 6 He at leading order (LO) within the EFT. Results: The nn virtual state and the 2 P 3/2 resonance in 5 He give the two-body amplitudes which are input to our LO three-body Halo EFT calculation. We find that without a genuine three-body interaction the two-neutron separation energy S 2n of 6 He is strongly cutoff dependent. We introduce a nnα "three-body" operator which renormalizes the system, adjusting its coefficient to reproduce the S 2n of 6 He. The Faddeev components are then cutoff independent for cutoffs of the order of, and above, the breakdown scale of the Halo EFT. Conclusions: As in the case of a three-body system where only resonant s-wave interactions are present, one three-body input is required for the renormalization of the EFT equations that describe 6 He at LO. However, in contrast to the s-wave-only case, the running of the LO nnα counterterm does not exhibit discrete scale invariance, due to the presence of the p-wave nα interaction.

show abstract

“…Halo EFT was first formulated in refs. [17,18] in their study of the shallow p-wave neutron-alpha resonance and applied to other systems, such as the s-wave alphaalpha resonance [19,20], three-body halo nuclei [21,22], and proton- 7 Li in a recent coupled-channel extension [23]. In this work, the tight 7 Li core, inert and structureless at leading order (LO), the loosely bound neutron, and the external soft photons are the relevant degrees of freedom.…”

Section: Introductionmentioning

confidence: 99%

Leading E1 and M1 contributions to radiative neutron capture on lithium-7

Fernando¹,

Higa²,

Rupak³

2012

Eur. Phys. J. A

View full text Add to dashboard Cite

Abstract. Using halo effective field theory, we provide a model-independent calculation of the radiative neutron capture on lithium-7 over an energy range where the contribution from the 3 + resonance becomes important. We also present power counting arguments that establish a hierarchy for electromagnetic oneand two-body currents. One finds that a satisfactory description of the capture reaction, in the present single-particle approximation, requires a resonance width about three times larger than the experimentally quoted value.

show abstract

Range corrections for two-neutron halo nuclei in effective theory

Cited by 46 publications

References 65 publications

Combiningab initiocalculations and low-energy effective field theory for halo nuclear systems: The case of7Li+n→8Li+γ

Combiningab initiocalculations and low-energy effective field theory for halo nuclear systems: The case of7Li+n→8Li+γ

He6nucleus in halo effective field theory

Leading E1 and M1 contributions to radiative neutron capture on lithium-7

Contact Info

Product

Resources

About