Nuclear Theory·nucl-th

Monday·November 9, 2020

6 papers—3 primary·3 cross-listed

04
Estimating the nuclear saturation parameter via low-mass neutron star asteroseismology
Hajime Sotani
We examine the fundamental ( $f$ -) and the 1st pressure ( $p_{1}$ -) mode frequencies in gravitational waves from cold neutron stars constructed with various unified realistic equations of state. With the calculated frequencies, we derive the empirical formulae for the $f$ - and $p_{1}$ -mode frequencies, $f_{f}$ and $f_{p_{1}}$ , as a function of the square root of the stellar average density and the parameter ( $η$ ), which is a combination of the nuclear saturation parameters. With our empirical formulae, we show that by simultaneously observing the $f$ - and $p_{1}$ -mode gravitational waves, when $1.5 ≲ f_{p_{1}} / f_{f} ≲ 2.5$ (which corresponds to neutron star models with the mass of $≲ 0.9 M_{⊙}$ ), one could estimate the value of $η$ within $\sim 10%$ accuracy, which makes a strong constraint on the EOS for neutron star matter. In addition, we find that the maximum $f$ -mode frequency is strongly associated with the minimum radius of neutron star. That is, if one would observe a larger frequency of the $f$ -mode, one might constrain the upper limit of the minimum neutron star radius.
↳ astro-ph.HEnucl-thPRD(2020)·21 citations
05
Covariant formulation of gluon self-energy in presence of ellipsoidal anisotropy
Ritesh Ghosh🇮🇳 · Bithika Karmakar🇮🇳 · Arghya Mukherjee🇮🇳
In this work, a covariant formulation of the gluon self-energy in presence of ellipsoidal anisotropy is considered. It is shown that the general structure of the gluon self-energy can be written in terms of six linearly independent projection tensors. Similar to the spheroidal anisotropy, mass scales can be introduced for each of the collective modes considering the static limits. With a simplified ellipsoidal generalization of the Romatschke-Strickland form, the angular dependencies of the mass scales are studied. It is observed that, compared to the spheroidal case, additional unstable mode may appear in presence of ellipsoidal anisotropy depending upon the choice of the parameters.
↳ hep-phnucl-thPRD(2020)·10 citations
06
Partial decay widths of $ϕ (2170)$ to kaonic resonances
Brenda B. Malabarba🇧🇷 · Xiu-Lei Ren🇩🇪 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷
In this work we study the strong decays of $ϕ (2170)$ to final states involving the kaonic resonances $K (1460)$ , $K_{1} (1270)$ and $K_{1} (1400)$ , on which experimental data have recently been extracted by the BESIII Collaboration. The formalism developed here is based on interpreting $ϕ (2170)$ and $K (1460)$ as states arising from three-hadron dynamics, which is inspired by our earlier works. For $K_{1} (1270)$ and $K_{1} (1400)$ we investigate different descriptions, such as a mixture of states belonging to the nonet of axial resonances, or the former one as a state originating from the vector-pseudoscalar dynamics. The ratios among the partial widths of $K^{+} (1460) K^{-}$ , $K_{1}^{+} (1400) K^{-}$ and $K_{1}^{+} (1270) K^{-}$ obtained are compatible with the experimental results, reinforcing the three-body nature of $ϕ (2170)$ . Within our formalism, we can also explain the suppressed decay of $ϕ (2170)$ to $K^{*} (892) K ˉ^{*} (892)$ , as found by the BESIII Collaboration. Furthermore, our results can be useful in clarifying the properties of $K (1460)$ , $K_{1} (1270)$ and $K_{1} (1400)$ when higher statistics data would be available.
↳ hep-phnucl-thPRD(2021)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

Estimating the nuclear saturation parameter via low-mass neutron star asteroseismology

Covariant formulation of gluon self-energy in presence of ellipsoidal anisotropy

Partial decay widths of ϕ(2170) to kaonic resonances

Affiliations

Partial decay widths of $ϕ (2170)$ to kaonic resonances