Correlations between charge radii differences of mirror nuclei and stellar observables
P. Bano, Shrikant Pattnaik, M. Centelles, X. Viñas, T. R. Routray
Abstract
The correlation between the charge radii differences in mirror nuclei pairs and the neutron skin thickness has been studied with the so-called finite range simple effective interaction over a wide mass region. The so far precisely measured charge radii difference data within their experimental uncertainty ranges in the $^{34}\mathrm{Ar}\text{\ensuremath{-}}^{34}\mathrm{S}$, $^{36}\mathrm{Ca}\text{\ensuremath{-}}^{36}\mathrm{S}$, $^{38}\mathrm{Ca}\text{\ensuremath{-}}^{38}\mathrm{Ar}$, and $^{54}\mathrm{Ni}\text{\ensuremath{-}}^{54}\mathrm{Fe}$ mirror pairs are used to ascertain an upper limit for the slope parameter of the nuclear symmetry energy $L\ensuremath{\approx}100$ MeV. This limiting value of $L$ is found to be consistent with the upper bound of the NICER PSR $\mathrm{J}0740+6620$ constraint at $1\ensuremath{\sigma}$ level for the radius ${R}_{1.4}$ of $1.4{M}_{\ensuremath{\bigodot}}$ neutron stars. The lower bound of the NICER ${R}_{1.4}$ data constrains the lower limit of $L$ to $\ensuremath{\approx}70$ MeV. Within the range for $L=70--100$ MeV the tidal deformability ${\mathrm{\ensuremath{\Lambda}}}^{1.4}$ constraint, which is extracted from the GW170817 event at $2\ensuremath{\sigma}$ level, and the recent PREX-2 and CREX data on the neutron skin thickness are discussed.