Unified description of ${}^6$Li structure and deuterium-${}^4$He dynamics with chiral two- and three-nucleon forces

Abstract

Prototype for the study of weakly bound projectiles colliding on stable targets, the scattering of deuterium ($d$) on ${}^4$He ($\alpha$) is an important milestone in the search for a fundamental understanding of low-energy reactions. At the same time, it is also important for its role in the Big-bang nucleosynthesis of ${}^6$Li and applications in the characterization of deuterium impurities in materials. We present the first unified {\em ab initio} study of the ${}^6$Li ground state and $d$-${}^4$He elastic scattering using two- and three-nucleon forces derived within the framework of chiral effective field theory. The six-nucleon bound-state and scattering observables are calculated by means of the no-core shell model with continuum. %and are compared to available experimental data. We analyze the influence of the dynamic polarization of the deuterium and of the chiral three-nucleon force, and examine the role of the continuum degrees of freedom in shaping the low-lying spectrum of ${}^6$Li. We find that the adopted Hamiltonian correctly predicts the binding energy of ${}^6$Li, yielding an asymptotic $D$- to $S$-state ratio of the ${}^6$Li wave function in $d+\alpha$ configuration of $-0.027$ in agreement with the value determined from a phase shift analysis of ${}^6$Li+${}^4$He elastic scattering, but overestimates the excitation energy of the first $3^{+}$ state by $350$ keV. The bulk of the computed differential cross section is in good agreement with data.

5 pages, 5 figures

References in corpus (13)

• Chiral effective field theory and nuclear forces
• Similarity Renormalization Group for Nucleon-Nucleon Interactions
• Local three-nucleon interaction from chiral effective field theory
• Three-Nucleon Low-Energy Constants from the Consistency of Interactions and Currents in Chiral Effective Field Theory
• Evolution of Nuclear Many-Body Forces with the Similarity Renormalization Group
• Unified ab initio approach to bound and unbound states: no-core shell model with continuum and its application to 7He
• Evolving Nuclear Many-Body Forces with the Similarity Renormalization Group
• High-energy break-up of 6Li as a tool to study the Big-Bang nucleosynthesis reaction 2H(alpha,gamma)6Li
• The Unitary Correlation Operator Method from a Similarity Renormalization Group Perspective
• {Once more about astrophysical $S$ factor for the $\alpha +d\to {}^6\mathrm{Li}+\gamma$ reaction
• ${}^4\mathrm{He}$+$n$+$n$ continuum within an ab initio framework
• A Predictive Theory for Elastic Scattering and Recoil of Protons from ${}^4$He
• Continuum and Three-Nucleon Force Effects on 9Be Energy Levels

Cited by in corpus (14)

• Quenching of single-particle strength from direct reactions with stable and rare-isotope beams
• Local nucleon-nucleon and three-nucleon interactions within chiral effective field theory
• Optical potentials for the rare-isotope beam era
• Calculation of the ${}^6$Li ground state within the hyperspherical harmonic basis
• Quantifying uncertainties in neutron-alpha scattering with chiral nucleon-nucleon and three-nucleon forces
• Ab initio prediction of the ${}^4\mathrm{He}(d,\gamma ){}^6\mathrm{Li}$ big bang radiative capture
• Gamow shell model description of ${}^4$He($d$,$d$) elastic scattering reactions
• Efficacy of the symmetry-adapted basis for ab initio nucleon-nucleus interactions for light- and intermediate-mass nuclei
• Nuclear Resonances, Scattering and Reactions from First Principles: Progress and Prospects
• Local two- and three-nucleon chiral interactions
• Quantifying uncertainties due to irreducible three-body forces in deuteron-nucleus reactions
• Updated three-body model of ${}^6$He $\beta$ decay into the $\alpha$ + $d$ continuum
• Light antiproton-nucleus systems at low energies with the ab initio NCSM/RGM method
• Theoretical calculation of nuclear reactions of interest for Big Bang Nucleosynthesis