${}^7$Be and ${}^7$Li nuclei within the no-core shell model with continuum

Abstract

The production of ${}^7$Be and ${}^7$Li nuclei plays an important role in primordial nucleosynthesis, nuclear astrophysics, and fusion energy generation. The ${}^3\mathrm{He}(\alpha ,\gamma {)}^7\mathrm{Be}$ and ${}^3\mathrm{H}(\alpha ,\gamma {)}^7\mathrm{Li}$ radiative-capture processes are important to determine the ${}^7$Li abundance in the early universe and to predict the correct fraction of pp-chain branches resulting in ${}^7$Be versus ${}^8$B neutrinos. In this work we study the properties of ${}^7$Be and ${}^7$Li within the no-core shell model with continuum (NCSMC) method, using chiral nucleon-nucleon interactions as the only input, and analyze all the binary mass partitions involved in the formation of these systems. The NCSMC is an ab initio method applicable to light nuclei that provides a unified description of bound and scattering states and thus is well suited to investigate systems with many resonances and pronounced clustering like ${}^7$Be and ${}^7$Li. Our calculations reproduce all the experimentally known states of the two systems and provide predictions for several new resonances of both parities. Some of these new possible resonances are built on the ground states of ${}^6$Li and ${}^6$He, and thus represent a robust prediction. We do not find any resonance in the p${+}^6$Li mass partition near the threshold. On the other hand, in the p${+}^6$He mass partition of ${}^7$Li we observe an $S$-wave resonance near the threshold producing a very pronounced peak in the calculated S factor of the ${}^6\mathrm{He}(\mathrm{p},\gamma {)}^7\mathrm{Li}$ radiative-capture reaction, which could be relevant for astrophysics and its implications should be investigated.

References in corpus (17)

• Similarity Renormalization Group for Nucleon-Nucleon Interactions
• Nuclear Charge Radii of Be-7,9,10 and the one-neutron halo nucleus Be-11
• Evolution of Nuclear Many-Body Forces with the Similarity Renormalization Group
• Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy
• Astrophysical S-factor of the 3He(alpha,gamma)7Be reaction measured at low energy via prompt and delayed gamma detection
• Microscopic calculation of the 3He(alpha,gamma)7Be and 3H(alpha,gamma)7Li capture cross sections using realistic interactions
• The 3He + 4He --> 7Be Astrophysical S-factor
• LUNA: Status and Prospects
• Ab initio predictions for polarized DT thermonuclear fusion
• Unitary Correlation Operator Method and Similarity Renormalization Group: Connections and Differences
• Activation measurement of the 3He(a,g)7Be reaction cross section at high energies
• Nuclear-matter distribution in the proton-rich nuclei ${}^7$Be and ${}^8$B from intermediate energy proton elastic scattering in inverse kinematics
• Cross section of ${}^3$He($\alpha$,$\gamma$)${}^7$Be around the ${}^7$Be proton separation threshold
• First Measurement of the $B(E2;3/2^{-}\to 1/2^{-})$ Transition Strength in ${}^7$Be: Testing Ab Initio Predictions for $A=7$ Nuclei
• Theoretical calculation of the $p-{}^6\mathrm{Li}$ radiative capture reaction
• Constraining the ${}^7$Be($p,\gamma$)${}^8$B $S$-factor with the new precise ${}^7$Be solar neutrino flux from Borexino
• Astrophysical ${}^3\mathrm{He}(\alpha ,\gamma {)}^7\mathrm{Be}$ and ${}^3\mathrm{H}(\alpha ,\gamma {)}^7\mathrm{Li}$ direct capture reactions in a potential model approach

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• A Guided Tour of Ab Initio Nuclear Many-Body Theory
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• Quantifying uncertainties in neutron-alpha scattering with chiral nucleon-nucleon and three-nucleon forces
• Emergent Sp(3,R) dynamical symmetry in the nuclear many-body system from an ab initio description
• Ab initio study of the beryllium isotopes ${}^7$Be to ${}^{12}$Be
• Probing ab initio emergence of nuclear rotation
• Solar fusion III: New data and theory for hydrogen-burning stars
• Towards Precision Muonic X-Ray Measurements of Charge Radii of Light Nuclei
• Robust ab initio prediction of nuclear electric quadrupole observables by scaling to the charge radius
• Analysis of the ${}^3\mathrm{He}(\alpha ,\gamma {)}^7\mathrm{Be}$ and ${}^3\mathrm{H}(\alpha ,\gamma {)}^7\mathrm{Li}$ astrophysical direct capture reactions in a modified potential-model approach
• Description of alpha-clustering of 8Be nucleus states in high-precision theoretical approach
• Asymptotic characteristics of decay channels of light nuclei states in the ab initio approach
• Ab initio estimation of $E2$ strengths in ${}^8$Li and its neighbors by normalization to the measured quadrupole moment
• Progress in Nuclear Astrophysics of East and Southeast Asia
• Gamow shell model predictions for six-proton unbound nucleus ${}^{20}$Si
• Towards the continuum coupling in nuclear lattice effective field theory I: A three-particle model