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| Title: | Density-Dependent Nuclear Interactions and the Beta Decay of 14C: Chiral Three-Nucleon Forces and Brown-Rho Scaling
Work supported in part by BMBF, GSI and by the DFG cluster of excellence: Origin and Structure of the Universe. |
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| Source: | FROM NUCLEI TO STARS Festschrift in Honor of Gerald E Brown (pp 187-221) |
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| Author(s): | J. W. Holt
Physik Department, Technische Universität München, D-85747 Garching, Germany N. Kaiser Physik Department, Technische Universität München, D-85747 Garching, Germany W. Weise Physik Department, Technische Universität München, D-85747 Garching, Germany |
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| Abstract: | We study the role of density-dependent low-momentum nucleon-nucleon interactions in describing the anomalously long beta decay lifetime of 14C. We approach this problem both from the perspective of chiral effective field theory, in which genuine three-body forces generate an effective density-dependent two-body interaction, as well as from the perspective of Brown-Rho scaling, in which the masses and form factor cutoffs in one-boson-exchange interactions are modified in a dense nuclear medium due to the partial restoration of chiral symmetry. The beta decay transition of 14C to the ground state of 14N is calculated within the shell model using a model space consisting of two 0p-shell holes within a closed 16O core. The effective 0p-shell interaction is calculated up to second order in perturbation theory with single-particle energies extracted from experiment. We find that both three-nucleon forces and Brown-Rho scaling medium modifications give qualitatively similar results not only for the ground state to ground state Gamow-Teller transition but also for Gamow-Teller transitions from excited states of 14C to the ground state of 14N. In this way, it is observed that at a low-momentum scale of Λlow−k = 2.1 fm−1, medium-modifications of the nuclear force play an essential role in increasing the lifetime of 14C from a few minutes to an archaeologically long one of 5730 years. | |
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