Search arXiv⌕ Search

arXiv · 1309.4845

In medium eta' mass and eta' N interaction based on chiral effective theory

Abstract

The in-medium eta' mass and the eta'N interaction are investigated in an effective theory based on the linear realization of the SU(3) chiral symmetry. We find that a large part of the eta' mass is generated by the spontaneous breaking of chiral symmetry through the U_A (1) anomaly. As a consequence of this observation, the eta' mass is reduced in nuclear matter where chiral symmetry is partially restored. In our model, the mass reduction is found to be 80MeV at the saturation density. Estimating the eta' N interaction based on the same effective theory, we find that the eta' N interaction in the scalar channel is attractive sufficiently to form a bound state in the eta' N system with a several MeV binding energy. We discuss the origin of attraction by emphasizing the special role of the sigma meson in the linear sigma model for the mass generation of eta' and N.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Shuntaro Sakai, Daisuke Jido. 2013-11-09. In medium eta' mass and eta' N interaction based on chiral effective theory. https://doi.org/10.1103/physrevc.88.064906

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

The renormalization of the shell-model neutrinoless double-beta decay operator starting from effective field theory at leading order

In this work, we approach for the first time the task to perform a shell-model calculation of the matrix element for the neutrinoless double-beta decay, within a fully-consistent framework where the expressions of the nuclear Hamiltonian and of the decay operators have been derived through chiral perturbation theory. More precisely, the effective shell-model Hamiltonian and all transition operators have been constructed by way of the many-body perturbation theory, and then employed to calculate both spectroscopic properties of the nuclei involved in the decays under our consideration - namely 48Ca, 76Ge, and 82Se -, as well as the nuclear matrix elements of the electromagnetic and neutrinoless double-beta decays. We also present a study of the convergence properties of the calculated matrix elements in order to provide the elements for an estimate of the theoretical uncertainty.

nucl-th↗

A new type of skin thickness in high-spin isomers to constrain equation of state of spin-polarized nuclear matter

We explore experimental probes for constraining the equation of state (EOS) of spin-polarized nuclear matter, where spins of nucleons are aligned along a particular direction. For this purpose, we calculate the $12^+$ isomeric state of the \ce{^{52}Fe} nucleus with the relativistic point-coupling model. We argue that the spin skin thickness of this high-spin state, that is, the difference between the radius of the spin-up density and that of the spin-down density, strongly correlates with the spin slope parameter of the EOS. This is in analogy to the well known linear correlation between the slope parameter of the symmetry energy and the neutron skin thickness of finite nuclei. We show that this correlation is retained even when one considers the difference of the radii between the $12^+$ and the ground states, even though the correlation is much weaker than in the case of the difference between the spin-up and the spin-down radii. We also discuss the mean-square charge radii of the $12^+$ state. We find that by taking the square of the radii the dependence on the spin slope parameter becomes much stronger, and thus it can serve as a good probe of the spin slope parameter given a high resolution of laser-spectroscopy experiments.

nucl-th↗

A Quantization-Constrained Parameter Method for Studying $α$ and Cluster Decay

We propose a Quantization-Constrained Parameter Method (QCPM) for determining the Woods-Saxon (WS) potential depth $V_0$ and diffuseness $a$ in studies of $α$ and cluster decay half-lives. In this approach, the parameters are derived analytically by imposing the Bohr--Sommerfeld (BS) quantization condition, thereby eliminating the need for parameter fitting. The calculated diffuseness values exhibit a strong dependence on nuclear shell structure. The reliability of the QCPM-derived WS potential is validated through optical model analyses of elastic $α$ scattering data. The resulting $α$ and cluster decay half-lives show good agreement with experimental values. Our results highlight the significant role of daughter-nucleus deformation in improving the consistency between theoretical predictions and experimental data. In addition, we introduce a modified Woods--Saxon (mWS) potential that effectively approximates the surface behavior of folding potentials incorporating the nuclear medium effect. This modification leads to closer agreement with the measured half-lives. Free of adjustable parameters such as $V_0$ and $a$, the QCPM enhances the predictive power of phenomenological potentials for $α$ and cluster decay studies.

nucl-th↗