Nuclear Mass Measurements Map the Structure of Atomic Nuclei and Accreting Neutron Stars

Abstract

We present mass excesses (ME) of neutron-rich isotopes of Ar through Fe, obtained via TOF-$B\rho$ mass spectrometry at the National Superconducting Cyclotron Laboratory. Our new results have significantly reduced systematic uncertainties relative to a prior analysis, enabling the first determination of ME for ${}^{58,59}\mathrm{Ti}$, ${}^{62}\mathrm{V}$, ${}^{65}\mathrm{Cr}$, ${}^{67,68}\mathrm{Mn}$, and ${}^{69,70}\mathrm{Fe}$. Our results show the $N=34$ subshell weaken at Sc and vanish at Ti, along with the absence of an $N=40$ subshell at Mn. This leads to a cooler accreted neutron star crust, highlighting the connection between the structure of nuclei and neutron stars.

Accepted for publication as a Rapid Communication in Physical Review C

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Cited by in corpus (11)

• Horizons: Nuclear Astrophysics in the 2020s and Beyond
• $B\rho$-defined isochronous mass spectrometry: a new approach for high-precision mass measurements of short-lived nuclei
• A new study of the $N=32$ and $N=34$ shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI
• Summit of the N=40 Island of Inversion: precision mass measurements and ab initio calculations of neutron-rich chromium isotopes
• Mapping the $N=40$ Island of Inversion: Precision Mass Measurements of Neutron-rich Fe Isotopes
• Examining the $N$ = 28 shell closure through high-precision mass measurements of ${}^{46-48}$Ar
• Improved description of nuclear charge radii: Global trends beyond $N=28$ shell closure
• Large enhancement of total reaction cross sections at the edge of the island of inversion in Ti, Cr, and Fe isotopes
• Improved Nuclear Physics Near $A=61$ Refines Urca Neutrino Luminosities in Accreted Neutron Star Crusts
• Nuclear Reactions in Evolving Stars
• Urca Nuclide Production in Type-I X-ray Bursts and Implications for Nuclear Physics Studies