Thu·Aug 17, 2023Thursday·August 17, 2023

1. 01*

   Precision mass measurement of ${}^{173}$Hf for nuclear structure of ${}^{173}$Lu and the $\gamma$ process

   A. Jaries🇫🇮 · M. Stryjczyk🇫🇮 · A. Kankainen🇫🇮 · T. Eronen🇫🇮 · Z. Ge🇩🇪 · M. Hukkanen🇫🇮 · I.D. Moore🇫🇮 · M. Mougeot🇫🇮 · A. Raggio🇫🇮 · W. Rattanasakuldilok🇫🇮 · J. Ruotsalainen🇫🇮

   We report on the precise mass measurement of the ${}^{173}$Hf isotope performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The new mass-excess value, $\mathrm{ME}=-55390.8(30)$ keV, is in agreement with the literature while being nine times more precise. The newly determined ${}^{173}$Hf electron-capture $Q$ value, $Q_{EC}=1490.2(34)$ keV, allows us to firmly reject the population of an excited state at 1578 keV in ${}^{173}$Lu and 11 transitions tentatively assigned to the decay of ${}^{173}$Hf. Our refined mass value of ${}^{173}$Hf reduces mass-related uncertainties in the reaction rate of ${}^{174}$Hf$(\gamma ,n{)}^{173}$Hf. Thus, the rate for the main photodisintegration destruction channel of the $p$ nuclide ${}^{174}$Hf in the relevant temperature region for the $\gamma$ process is better constrained.

   nucl-exEPJA(2023)·0 citations
2. 02*

   Constraints on the Nuclear Symmetry Energy from Experiments, Theory and Observations

   James M. Lattimer🇺🇸

   Nuclear mass measurements and neutron matter theory tightly constrain the nuclear symmetry energy parameters $J$, $L$, $K_{sym}$ and $Q_{sym}$. Corroboration of these constraints on $J$ and $L$ can be found from measurements of the neutron skin thicknesses and dipole polarizabilities of neutron-rich nuclei. The experimental constraints on these parameters are compared with those obtained from consideration of astrophysical measurements of the neutron star radius, which we show is highly correlated with $L$. Attention is aimed at the recent PREX and CREX neutron skin measurements from Jefferson Lab, NICER neutron star radius measurements, and a new interpretation of the GW170817 tidal deformability measurement. We find joint satisfaction of PREX and CREX gives $J=32.2\pm 1.7$ MeV and $L=52.9\pm 13.2$ MeV, in excellent agreement with neutron matter predictions of $J=32.0\pm 1.1$ MeV and $L=51.9\pm 7.9$ MeV.

   ↳ nucl-thastro-ph.HEnucl-exJ.Phys.Conf.Ser.(2023)·16 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.