Nucleon axial-vector coupling constant in magnetar environments

Abstract

The nucleon axial-vector coupling constant $g_A$ is studied in the presence of an external magnetic field, and in dense nuclear environments, to emulate nuclear matter in magnetars. For this purpose we use QCD finite energy sum rules for two-current and three-current correlators, the former involving nucleon-nucleon correlators and the latter involving proton-axial-neutron currents. As a result, the axial-vector coupling constant decreases both with baryon density as well as with magnetic field. The axial-vector coupling evaluated with baryon density near the nuclear density ${\rho }_0$ leads to $g_A^{\ast }\approx 0.92$. In the presence of magnetic fields $g_A$ decreases in general, but $g_A^{\ast }$ does not show significant changes.

8 pages, 6 figures. Minor corrections and one reference added. To be published in Phys. Rev. D

References in corpus (2)

• Value of the axial-vector coupling strength in $\beta$ and $\beta \beta$ decays: A review
• Magnetic effects of QCD parameters from finite energy sum rules

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• Do Finite Density Effects Jeopardize Axion Nucleophobia in Supernovae?
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• Strongly interacting matter in extreme magnetic fields
• Quark anomalous magnetic moment in an extreme magnetic background from perturbative QCD
• The Yukawa potential under weak magnetic field
• Finite-energy sum rules at finite chemical potential and zero temperature