Related papers: Nuclear Axial Currents from Scale-Chiral Effective…
The in-medium property of the axial-vector coupling constant $g_A$ in nuclei and dense baryonic matter, a long standing problem in nuclear physics, is reformulated in terms of the recently constructed scale-invariant hidden local symmetric…
I discuss how the axial current coupling constant $g_A$ renormalized in scale symmetric chiral EFT defined at a chiral matching scale impacts on the axial current matrix elements on beta decays in nuclei with and without neutrinos. The…
In light and medium-mass nuclei, two-body weak currents from chiral effective field theory account for a significant portion of the phenomenological quenching of Gamow-Teller transition matrix elements. Here we examine the systematic…
We show that chiral effective field theory (EFT) two-body currents provide important contributions to the quenching of low-momentum-transfer Gamow-Teller transitions, and use chiral EFT to predict the momentum-transfer dependence that is…
When scale symmetry is combined with chiral symmetry in a scale-chiral Lagrangian, it can be shown in Fermi-liquid fixed point theory that $g_A^{\rm eff}\approx 1$ in finite nuclei {\it as well as} in dense baryonic matter. This is…
How the axial coupling constant $g_A$ in nuclear Gamow-Teller transitions described in shell model gets "quenched" to a universal constant close to 1 can be explained by nuclear correlations in Fermi-liquid fixed point theory using a…
This brief note is to point out that the recent measurements at GSI and RIKEN of the superallowed Gamow-Teller transition in the doubly magic closed-shell nucleus $^{100}$Sn could give an indication for a possibly important {\it…
We study neutrinoless double-beta decay in an effective field theory (EFT) for heavy nuclei, which are treated as a spherical core coupled to additional neutrons and/or protons. Since the low-energy constants of the EFT cannot be fitted to…
For the first time, we approach in this work the problem of the renormalization of the Gamow-Teller decay operator for nuclear shell-model calculations by way of many-body perturbation theory, starting from a nuclear Hamiltonian and…
We study $\beta$ decays within an effective theory that treats nuclei as a spherical collective core with an even number of neutrons and protons that can couple to an additional neutron and/or proton. First we explore Gamow-Teller $\beta$…
It is widely accepted that nuclear Gamow-Teller transitions are quenched; shell-model calculations also showed a clear anticorrelation between the Gamow-Teller strength and the transition rate of the collective quadrupole excitation from…
How to disentangle the possible {\it genuine} quenching of $g_A$ caused by scale anomaly of QCD parameterized by the scale-symmetry-breaking quenching factor $q_{ssb}$ from nuclear correlation effects is described. This is done by matching…
The long-standing puzzle of the quenched $g_A$ in nuclei is shown to have an extremely simple resolution in a renormalization-group (RG) treatment of a hidden local symmetric (HLS) and scale-symmetric (HSS) chiral Lagrangian. It is shown…
An ``unorthodox" idea is developed that the long-standing mystery in nuclear physics of the effective axial-current coupling constant in nuclei, $g_A^{\rm eff}\approx 1$, could be interpreted in terms of an emerging hidden scale symmetry in…
The superallowed Gamow-Teller transition in the doubly-magic-shell nucleus $^{100}$Sn and the high resolution spectral shape analysis in the fourth-forbidden nonunique transition in $^{115}$In indicate as much as $\sim 40\%$ {\it…
A recent RIKEN experiment on the quenched $g_A$ in the superallowed Gamow-Telller transition from $^{100}$Sn indicates a role of scale anomaly encoded in the anomalous dimension $\beta^\prime$ of the gluonic stress tensor ${\rm Tr \…
Gamow-Teller transitions in nuclei tell us that the nucleon's axial charge $g_A^{(3)}$ is quenched in large nuclei by about 20%. This result tells us that the spin structure of the nucleon is modified in nuclei and disfavours models of the…
We discuss the uncertainties in constraining low-energy constants of chiral effective field theory from $^3$H $\beta$ decay. The half-life is very precisely known, so that the Gamow-Teller matrix element has been used to fit the coupling…
Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory, and accounts for cancellations between the contributions of irreducible…
The longstanding quenching problem of Gamow-Teller (GT) strength in nuclear $\beta$-decay is attributed to missing contributions in the transition operator and/or incomplete nuclear correlations in the many-body wavefunction. Recent studies…