Systematics of 2+ states in C isotopes from the ab initio no-core shell model

Abstract

We study low-lying states of even carbon isotopes in the range A = 10 - 20 within the large- scale no-core shell model (NCSM). Using several accurate nucleon-nucleon (NN) as well as NN plus three-nucleon (NNN) interactions, we calculate excitation energies of the lowest 2+ state, the electromagnetic B(E2; 2+1 -> 0+1) transition rates, the 2+1 quadrupole moments as well as se- lected electromagnetic transitions among other states. Recent experimental campaigns to measure 2+-state lifetimes indicate an interesting evolution of nuclear structure that pose a challenge to reproduce theoretically from first principles. Our calculations do not include any effective charges or other fitting parameters. However, calculated results extrapolated to infinite model spaces are also presented. The model-dependence of those results is discussed. Overall, we find a good agree- ment with the experimentally observed trends, although our extrapolated B(E2; 2+1 -> 0+1) value for 16C is lower compared to the most recent measurements. Relative transition strengths from higher excited states are investigated and the influence of NNN forces is discussed. In particular for 16C we find a remarkable sensitivity of the transition rates from higher excited states to the details of the nuclear interactions.

22 pages, 8 figures, preprint version. Accepted for publication in Journal of Physics G: Nuclear and Particle Physics

References in corpus (15)

• Recent developments in no-core shell-model calculations
• Three-Nucleon Low-Energy Constants from the Consistency of Interactions and Currents in Chiral Effective Field Theory
• Similarity-Transformed Chiral NN+3N Interactions for the Ab Initio Description of 12-C and 16-O
• Evolution of Nuclear Many-Body Forces with the Similarity Renormalization Group
• Ab initio no-core full configuration calculations of light nuclei
• Importance Truncation for Large-Scale Configuration Interaction Approaches
• Corrections to nuclear energies and radii in finite oscillator spaces
• Convergence properties of {\itshape ab initio} calculations of light nuclei in a harmonic oscillator basis
• Effective operators within the ab initio no-core shell model
• Lifetime measurements of first excited states in 16,18C
• Operator Evolution via the Similarity Renormalization Group I: The Deuteron
• Charge radii and electromagnetic moments of Li and Be isotopes from the ab initio no-core shell model
• Converging sequences in the ab initio no-core shell model
• On the lifetime of the 2+ state in 10C
• Microscopic shell-model description of the exotic nucleus ^{16}C

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